Previously I reviewed the kbd75v2 with split spacebar here
https://geekhack.org/index.php?topic=112840.0(my daily driver ever since, and I have 6 other TKLs which I probably will never use again because I can’t go back to non-split spacebar layout, all the benefits of the kbdv75 apply here)
Then I learned about the keebio SINC, which seems like even better because I can have 4 keys under the thumb cluster instead of kbdv75’s 3.
When the SINC restocked I immediately ordered one and then I found out there’s another KBO-5000 with exploded right cluster and 1x left macro column, which I preferred.
But most importantly the right spacebar on the SINC is vertically aligned with the ‘n’ key while the KBO-5000’s is .25u further out, which is where my right thumb naturally rests.
Compared to the kbdv75, the TKL placement of the home/end/page up/page down is miles better (still can’t locate those keys on the kbdv75 without looking), plus the left macro column for dedicated macro record/play, copy, cut, paste (ctrl insert, shift delete, shift insert on windows – which works across 99% apps including regular windows app + emacs/vim, cmd c, cmd x, cmd v on macos) works wonder when I’m using the mouse with the right hand. The encoder is a nice to have.
The only downside is that when using both halves in a split configuration, each half is too light and can move around ever slightly.
When pushed together it’s not bad if I use a desk mat. But I preferred having a solid aluminum case like the kbdv75.
And the atmega32u4 MCU (on both the kbo5000 and kbdv75) is showing its age. I have to disable absolutely every QMK feature I can spare so the firmware size won’t overflow. Hopefully STM32 will become mainstream going forward.
With one shot modifiers under the thumb, typing Capitalized words and keyboard shortcuts is effortless. I repurpose the left shift to activate a layer so I can use vim like motion on all apps, getting the best of both world (not having to move my hands away from home rows if I want, and with a TKL layout to have everything I need without accessing layer), while the right shift output ‘_’ when tapped.
With the HHKB backspace placement and additional Del under the thumb, this split configuration is way more ergonomic than all 60/65/HHKB layout.
Besides the MCU issue, the USB-c cable connecting the two halves can be quite finicky when you move the board around.
And one tiny improvement would be to move the Esc key above the Tilde (like the SINC) although I understand that the KBO5000 is a tribute to the OG cherry G80-5000.
But this is really a true gem since you don’t get to have such a flexible layout in traditional staggered format (you can find a lot of weird layouts with ortho), so I don’t have to relearn typing.
Will follow up with a long term review in some distant future. (Plus I have Dactyl 5x7 on the way, so I think I'm well covered with my almost end game ergonomic layout)