I have managed to avoid purchasing a keyboard for almost a year now. Apparently this is too long:
Today briefly before lunch, the "Alt" key on my Bluetooth DiNovo finally gave up the ghost. It's still under warranty, but I was in the middle of hacking with Emacs, and you can't really do that without a meta key. I really do destroy keyboards at an unbelieveable rate. As a backup, I purchased a somewhat sturdier and cheaper board; the Saitek Eclipse PC Keyboard.
While it doesn't meet any of my normal criterea for a good keyboard, i.e. it doesn't use mechanical keyswitches and it's not slim form-factor, something about this keyboard just exudes quality. This wasn't a dramatic or somehow amazing keyboard like the Tactile Pro, but it is a quietly comfortable and definitely high-quality keyboard. It's a bit paradoxical - I generally hate membrane keyboards with a lot of travel, but this one seems to be quite comfortable. The keys are a good size, the incline is comfortable, and I seem to be able to break 140wpm consistently in the hard drills at the end of gtypist. It has exactly the keys I need: no funky spatter of random "internet" function buttons that don't work with Linux anyway. All the keys are in exactly the right place; they didn't pull any weird tricks like expanding the Delete key, moving around the backslash or backquote, or sliding the Alt somewhere other than under the thumb. The nominal Control keys are nice and wide, when you need to use them, and the Caps Lock isn't castrated to make it useless as a Control.
But of course, these are all just mistakes they didn't make. It feels nice, and I don't know why. The only concrete difference I can really put my finger on (no pun intended) is the lack of "squeak". Perhaps there is a better word for this, but I have only tested this concept experientially - here's what I mean.
Try this with a normal $5 keyboard: push hard on one of the keys, then slide your finger back and forth. You will notice that it squeaks when you wiggle your finger back and forth, sending vibrations up your arm. I always take this as a sign of the quality of the construction of the keyboard, because the squeak is coming from bits of plastic rubbing against each other which are never really supposed to touch. On really awful keyboards this is bad enough that you can feel the squeak while typing; on others there is just the occasional hint of it.
While this particular feature isn't a deal-breaker for me (even the DiNovo has a tiny bit of squeak) it is definitely a good sign that the Eclipse doesn't have it. I'm enjoying typing on it immensely so far. Its first day it saw a prodigious amount of use, as I was preparing for a rather intense deadline :).