Type K or Mountain Ergo https://kbdfans.com/products/ic-kbdfans-mountain-ergo-keyboard-kit ?
This is a hypothetical question since ME is obviously discontinued already. But the designs are very similar.
Not sure what the other posters are basing their responses on, as they didn't elaborate on why they like the Type K over the Mountain Ergo, but I own 2 Mountain Ergo's. Here's how I'm currently weighing the 2 options:
TL;DR - Imo, without a Type K proto on hand to compare in-person with: Gok is a proven designer, has put a lot of thought into the Type K (TK), and there are more customization options available than there were for the Mountain Ergo (ME). It's a beautiful board. However, there are some compromises made in the design that make it impractical, especially considering it costs double (or more) what the Mountain Ergo did. Aesthetics and layout are subjective, and the only objective improvement is the customization available. I'm torn on whether its worth the pricetag.
Design & layoutThis is subjective, of course, but there are a number of things we can look at. They are two completely different styles - the Type K is modelled after the 7V and has more of a high-tech feel, with the LED bar, PC bottom, and exposed back weight. The Mountain is very angular and simple. I will say that due the sloped sides, the Mountain's are somewhat difficult to pick up with one hand, not sure how the TK'd fare there. Thematically, I'd say the angles fit the "mountain" theme. FWIW, I like the design of the ME, but it's not anything mind-blowing. The TK definitely has a more thoughtful design - though I can't say it's to my preferences. The indicator lights on the top are a nice touch. I like the overall aesthetic, but there are a couple of things that I don't like: the spacebars and the right mods.
The TK doesn't follow the typical 2u+2.25u or 2.25u+2.75u split spacebar layout. A lot of keycap base kits are coming with a set of 1x 2u+2.25u+2.75u spacebars, which is great for split spacebar users, but means that you will now generally have to buy an additional child kit to outfit the TK vs. the ME, and buying 2nd hand sets will be much harder down the road. I feel that base kits far outsell any child kits (extension/spacebars) in general, and that they are much harder to get extras of or find on the second hand market for sets that have already run. I get that gok was going for elements of symmetry in this board, but I don't think that the compromise was worth it for that alone. That said, a larger spacebar generally has a fuller sound, though I'm not sure a .25u size difference make that much of a difference. More on sound later.
Ok, the right mods. This is purely preference, but I really dislike the look of the right shift not lining up with the enter key, or extending beyond it. I also get that the single 1.5u mod below that is supposed to emulate the WKL look, but the fact that it's inset even further also looks weird. For me, a board that is focussed on symmetry, having the right side "retract" while the left side follows the traditonal alice "pyramid" layout looks really strange. I'd prefer if the right shift was a full 2.75u size, with a 1.75u + 1u option, with either 2 x 1.5u or 1.25u mod keys below that, either in line or extended slightly beyond the right shift. Again, this is also much better for keycap compatibility as 1.25u shifts are not as common as 1.75u ones.
I do like the TKs left-hand macro column though - I find that there aren't enough keys on the ME to show off novelties or artisans.
SoundThe ME only comes in alu top mount, love it or hate it. It has a very crisp and even sound, and the alphas are very satisfying to hammer away on. Mods sounds great, spacebars sound pretty good for an Alice layout. I tend to prefer clackier builds these days, and both of my boards err on that side. One is built with WS Onions and ePBT caps, while the other one is Cannoncaps CXA WoB (MTNU Susu can't come fast enough!) on Azure Dragons. I run them both with case foam, and no plate foam, as I do find the ME has a bit of case resonance without it, but only around the spacebars. They have a nice open, clean sound. Pretty standard for a well-implemented top mount alu plate.
With the soundtests I've heard for the TK, I have... mixed feelings. I think Makerchun's build with the PC plate sounds the best. It eliminates that resonance that everyone has been talking about here. Again, I can't say for sure since I don't have a Type K, but to me it sounds more resonant / hollow than my ME's do with no foam. I get that you get to hear some of the sound signature of a board with a bit more resonance, but it does seem to be a bit over the top for a keyboard of this class, with a PC bottom and SS weight. Using a PC plate, even if it doesn't cost extra (though I have a feeling it might), might also make it sound to plasticy. For the price, this seems like a bit of a risk. I will say that the spacebars do sound better to my ear on the TK on Makerchun's PC config. I have a weird issue with the ME where the cuts in the right plate around the spacebar make the switch
ever so slightly loose, and only on the one built with Azure Dragons, and since its hotswap there's nothing holding the switch in place. This makes the right space a little less satisfying that it should be. This doesn't appear to be the case with the TKs plates, as they are 1.5mm think and pretty solid, whereas the ME's plates are quite thin and have more matierial cut away.
Typing feelThe ME is fairly stiff, as is expected with no flex-cuts, and alu top mount. I have no complaints here, though I wish there was a PC plate available just to see if it would have some forgiveness to it, given that it's a keyboard focussed on ergonomics. I find that sometimes I get some fatigue in my fingers when I get going on the Azure Dragon build, though I think that's a personal issue. They are very tactile switches, have a long-pole stem, and I am a fairly heavy typist. I really enjoy hammering on heavy tactile switches. I never have this issue on the linear ME, as I tend not to type as heavy on linears.
I can't really comment on the TK, but from the videos it still looks somewhat stiff. But given that it's grommet mount and that there is a PC plate option, I think it's safe to assume that the TK will have a softer typing feel over the ME.
Finish/qualityI have both the e-white and ano black ME's. They are both smooth, even, and flawless, inside and out. The quality is top notch. The machining is also excellent, there are no scuffs, marks, or uneven lines, even on the tiny bevelled top edge, or on the plate lines cut out. I have nothing negative to say about the finish of my ME's, other than that my dumbass has put a couple tiny nicks into them when swapping them around.
Given gok's track record, I assume the TK will be the same, if not better. I will say that part of why I am drawn to the TK is the finishes - e-white and ano black are a bit basic. I'm really jealous that KBDFan's other ergo board, the Kunlun, came in all kinds of options, though those boards are too wide for me to consider purchasing one. The TK has 3 more interesting options, which is a plus in my book, and after all, a big part of keyboards is the looks and customization.
Other featuresAs I've mentioned, the ME was fairly limited in the options available. Its base configuration is good, but beyond foams and other standard modding, there isn't much to customize here.
The TK has way more options than the ME did. Finishes, plates, LED light bar, weights, and wrist rests. I haven't even mentioned the wrist rests. There are some really nice options, and very unique too. I like that gok has left open to option to possibly sell different shells in the future too. I personally don't use a wrist rest, so it's a moot point for me, though I see how that would be appealing to other people.
PriceThis is where things get a little hairy for me. From what I can tell from proto videos, each board has about an even number of pros and cons for me. I'm really happy with my ME's, but since I have an addiction like you all do, I'm always looking to add to my collection. There aren't a lot of tented ergos out there, so I've been watching this board for years now. However, I'm really tempted to buy another ME and just get it cerakoted if I want a new coloured board. I could get any colour I want, built with switches, stabs, and keycaps for probably the same price (or less) than a TK barebones kit.
I do really want the board, but I am a big believer in only keeping things if you really love them. A $750+ gamble for something that might be just ok, is a bitter pill to swallow, even if it comes from a notable figure in the space. I still have 2 weeks to decide, so we'll see how I feel at 11pm on the last day