This is a fascinating discussion for me.
I had been trying to replace the fading keycaps on my Filco Majestouch 2 back in August, which is what brought me into keyboard modding.
I went through a long process [DSA, SP Filco doubleshots, Chinese PBT] until I chanced upon some old DCS-profile keycaps from a Wyse terminal board.
The Wyse keycaps are thick double-shot ABS, and were made by the predecessor company of Signature Plastics.
Unlike modern SP DCS keycaps, the Wyse double-shots are actually thick, probably around 1.5mm, comparable to what is called 'thick PBT' from China.
The Wyse keycaps have provided the most comfortable typing experience on MX Browns on the Majestouch.
With MX Browns, you don't necessarily want thick PBT. It can further reduce the tactility of Browns, make them feel even more like scratchy reds. And you don't necessarily want OEM or tall profiles, because they emphasize the wobbliness of Cherry MX.
So thick ABS DCS is actually a great combination. What's different about DCS as compared to Cherry is that DCS feels a little more 'dished' or 'scooped' in the way it is contoured. Kind of like how MT3 profile is a little more rounded or sculpted when compared to SA profile.
It 'cups' the fingertips a little more.
When I placed DCS beside some Cherry-profiled keycaps that I have, the DCS seemed to be a little taller at the edges, but dished deeper, such that they appeared shorter.
This means that DCS is comfortable to type on, feeling a little less harsh or mechanistic compared to Cherry-profile. But because Cherry is less-indented, it is probably easier to rapidly switch between rows on Cherry-profile. [I notice my Varmilo keycaps are great for this, although they are SS2 profile].
So Cherry profile is probably slightly faster, and DCS is probably slightly more comfortable. That's my experience.
Also of note, and hard to come across over the internet, is that Wyse DCS sounds objectively better to me than GMK on a Filco with MX Browns.
GMK keycaps makes a chittery noise, almost insectile. Certainly high-pitched and plasticy. On the other hand, Wyse DCS are lower-pitched, producing a deeper 'clack' [really a medium noise as compared to thick PBT]. And they 'flutter' when pressed rapidly, especially on the numpad.
So Wyse DCS have a nicer sound than Cherry-profiled ABS like GMK. In general, DCS has greater sculpting than Cherry. It may be more comfortable for individual fingers, although perhaps not as fast as Cherry-profile.
So where do you get the good DCS keycaps? Others on this thread have pointed to DCS Midnight, on SP's website. I'm told that those are thin keycaps, unlike the old Wyse. Supposedly, they are less satisfying.
There is a set of DCS Midnight on sale here in Ontario for $70 CDN. They might even come with the limited-edition midnight modifiers. DCS Midnight is a visually-striking set, if nothing else. But it's thin ABS.
Getting the Wyse keycaps can't be that hard. They were pulled off by the hundreds by people farming vintage Blacks from the Wyse terminals. I have seen them for sale on Reddit's mechmarket, and you can find them at meetups.
But even if you do get them, you need a 'Moogle Kit' to adapt them to a modern board, and those are rare. [Search this forum for details on the Moogle Kit]. I was lucky enough to snag an additional set of Wyse keycaps plus two Moogle Kits from a U.S. citizen on mechmarket.
I now have two relatively complete sets. I am currently typing this message on vintage beige Wyse keycaps and some beige modifiers from a Moogle Kit. I also have a vintage gray/blue set and accompanying Moogle Kit. [A full vintage Wyse set plus two Moogle Kits will run you about 100 USD].
So that's your best bet for good DCS. These keycaps have not been surpassed in typing experience on light tactiles on my board.*
The only problem, as indicated elsewhere, is that DCS has a very steep bottom row. I am using an ePBT 9009 spacebar instead of DCS, because it is angled too high otherwise.
*It also reminds me that the alleged 'snobbery' on this board and especially Deskthority for vintage keycaps and switches is completely justified. It seems as if a number of manufacturers reached the top of their game in the 1980s and 1990s and were never surpassed, even by today's 'custom' producers.
