Bottom rows of profile R4 + R4 vs R4 + R5: how different is that?

[menuhin]

Not until recently I just realized most of the keysets have their bottom two rows (the 'Z' row and the space bar and Ctrl Alt row) designed as R4 + R4 profile (e.g. GMK Dolch, Hyperfuse, etc)
There's obviously also the R4 and R5 bottom row profile in some older keysets and a few new one, for example this GMK WoB:


How big of a difference does the two profile settings give you? Why there aren't too many R4+R5 keysets out there nowadays?

[nyunyu]

Cherry used A row profile (R5 in GMK's terminology) in the early nineties.

Original Shift (B/R4) and Ctrl (A/R5) caps from a vintage G80-1000HFD:


But in '95 they added the windows keys, and since then they are not using that row profile any more.
Newer Cherry keyboards use B row profile (=R4) for Ctrl/Alt/Win keys (same as Shift.)

[ideus]

That white on black set is one of the very few that include the now forgotten Row A bottom row, as an option. It even includes a Row A windows key.

Regarding your questions. You can really feel the difference between Row B and Row A profiles. The last is very angled, therefore your thumbs and pinkies will feel the difference for sure. I can use both; but, I prefer the Row A for the bottom row.

[TalkingTree]

R4 on the left, R5 on the right.

[Slash Emperor]

I've got some RGB mods from an old and rare Desko set that are vintage Row A on my Leeku 1800 and I love the angle. It's really nice to have on my Ctrl and Alt (1.5u), wish I had more vintage Row A caps in 1.5 and 1.25u.