Yeah, that's what I meant. I find that I tend to exclusively use my left thumb for space (using my right thumb on purpose feels weird, though I'm sure I could get used to it if necessary). So my plan was to use right-space for esc. But this realization of not having alt+tab on one hand might make me use it for alt instead... I think a solution can be found.
Aye, there are loads of possibilities. Putting esc on the left Ctrl key like you suggested and using either of the space bars for Ctrl instead could be a nice option I'd think, though historically using thumb for the "main" modifier key might be more of a Mac thing (I'd call Command the main modifier for Mac OS, and Ctrl for Win/Linux/...)
So maybe I *shouldn't* try to switch to Colemak at the same time as giving the TECK a go...
Not sure, it could make sense to combine the two periods of "unproductiveness" into one. What I meant is that one is up to acceptable speed with a new keyboard within hours (longer to get really comfortable), whereas it "usually" takes days/weeks to get there with a new layout.
My experience as an example: I could type at least half of my normal speed with the TrulyErgonomic immediately (though I am already used to a grid layout, so YMMW), whereas it took me 3 weeks to get to half my normal speed with Colemak. Getting back to full speed with the Advantage took roughly 3 weeks, whereas it took almost a year with Colemak (I switched to my current Advantage keyboard roughly half a year after switching to Colemak, I wrote about it at the Colemak forum
if you're interested). This is of course highly subjective, I suggest checking out the experience threads at the Colemak forums for more variety.
Unfortunately given their funny keycaps it seems unlikely we'd be able to get a good group buy going for the TECK. Then again I'm still pretty new to this community so maybe someone knows better.
The center column key caps do look quite special :-/, I'll try replacing some others with WASD key caps at some point.