When you've bought your third expensive keyboard it's time to admit you have a
fetish.  Or that you spend most of your day glued to the business end of a
computer.  Or both!  But face it: if you spend a lot of time writing, a decent
keyboard is worth more than its weight in gold, for reasons of efficiency,
health, and comfort alone.

I was in the mood for a keyboard built around a linear (not-staggered) layout,
and a few reviews of the TEK ("Totally Ergonomic Keyboard") made it
seem appealing.  So I bought one and have used it for the past couple of weeks.
Here are my conclusions, and a few notes of comparison with the Kinesis Ergo
keyboard, which I also like and use daily.  First, this keyboard is expensive.
But it is worth the money for the build quality alone.  It's solid: the keys
are made of a solid, thick feeling plastic you don't appreciate until you go
back to something designed using flimsier specifications, and it's generally
well-laid out.  Unlike the Kinesis, the function keys are built just like every
other key, which I like.  There's a wrist rest you could remove if you
preferred, but it requires unfastening nine screws to do so, which indicates to
me you are really expected to use it.  But it's extremely well made, so that's
not a huge problem.  And a huge level of effort has gone into really detailed
design and building.  It even comes with a custom-fit, plastic dust cover for
the end of the day: I live in a dusty climate and eventually my keyboards look
like they were dipped in mud, so this is a nice little extra that probably cost
very little but makes a big different.

Layout issues: The linear layout is different and takes a day or two to get
used to.  But once you get accustomed to it you'll find it's a bit faster, and
the spectacular key switches are comfortable, give great tactile feedback, and
aren't tiring.  There's no question about mechanical keyboards being superior.
I had a few problems getting used to specific keys: I now use my second finger
to strike the C instead of my first; that took some getting used to.  I also
had trouble getting used to the apostrophe being to the right of the P instead
of directly to the right.  And the hardest one of all was finding the square
and angle brackets where my left pinky was expecting to find the tab key: that
one still haunts me.  I like very much having the Control key under my left
pinky (and now, my right pinky too!).  Having backspace, delete, and Super
("Win" or "Command") in the middle has worked fine for me.  Having the
Home/End/Page Up/Page Down cluster under the left hand, and the
up/down/left/right arrows clustered under the right hand has been very nice.  I
find myself using Home and End quite a bit more now that it's not quite such a
pain to reach for them each time.

Complaints?  The escape key is really far away.  That makes this keyboard
slightly annoying for editing with the Vim text editor, for which I still
prefer my Happy Hacking Keyboard.  And the tab key is a bit small.  Lastly, the
Alt keys are nice and big, but you've really got to reorient your hands in
order to find them.  I'm still toying with the idea of making the left space
bar and Alt key since I instinctively hope to find it under my left thumb, and
apparently I only use my right hand for spaces anyway.  The fact that you can
remap any key to any character makes that possible and is a huge benefit!  That
also makes the Alt-Tab key combination for moving among windows slightly
awkward (on my Linux machine I simply chose a more comfortable combination:
hooray for configurability under KDE!).  None of these things is a real
deal-breaker, and the custom configurability makes it easy to adjust.

Conclusion:  I'm definitely keeping this keyboard, and it's currently my
favorite.  It's comfortable, well-made, and lovely to use.  The attention to
comfortable keypresses is obvious - the actuation pressure, clickiness, and
like are all superb.  Having the wrists straight instead of pronated seems
useful, though that was never a source of discomfort for me.  But the
mechanical key switches and build quality of this keyboard make it a real
lifestyle-improvement.  It seems made of higher quality materials than the
Kinesis, and its keys are less wobbly.  I still love the ergonomics of the
Kinesis, but this seems to work well too.  I will certainly continue to use
them both, as the Kinesis is more comfortable but the TEK has nicer key action.