top tier (1) - kinesis/maltron/ergodox
middle tier (2) - truly ergonomic/microsoft ergo 4k/goldtouch/kinesis freedom
bottom tier (3) - basic split keyboard/basic mechnical TKL
Tiers should be done by measurable elements. Ergodox is not on the same tier as Kinesis Advantage. Maltron and Kinesis have contoured keyboards.
Tier 1: contoured keyboards.
Tier 2: Split keyboards non contoured. (TEK, Ergodox)
So then we need another classification for mechanical vs non mechanical.
And then, you have topre switches that are not mechanical, but not cheap rubber dome.
Now, MS4k has low quality, and terribly cheap rubber dome switches, but the layout, the shape and comfort it provides is really good. I would not put it in bottom tier, ever. Modifiers are big and symmetrical, and kicks the matias unreleased ergo layout ass easily.
The only thing we can agree to have fixed tiers are on prices. Or maybe bang for the buck (in that case MS4k beats kinesis and ergodox hands down)
So there are many categories, that it's impossible to make a certain tier. Plus some cons are pros.
For example:
Programability (tier 1: Ergodox, tier 2: Kinesis Adv)
Easy to program (Tier 1: Kinesis, Tier 2: ergodox)
I would not put Microsoft Ergo in the same class as Goldtouch and Truly Ergonomic and Kinesis Freestyle. It's a class below, in my view.
I suggest adding the microTron keyboard to the top tier. It's split, Topre, has thumb keys, and the layout is innovative. While not having straight columns, the staggering is symmetrical on both sides. Also, the firmware has built-in support for DVORAK. To lump that with a simple split keyboard like Goldtouch would be an insult to the microTron designers, in my view.
I beg to differ. the microTron has 3 bottom keys, that are supposedly touched with the thumbs. If you do that for the last 2 keys, you will generate a serious problem on your health. Curling your fingers inwards to type is an anti ergonomic design.