The device itself is rock solid. Like most current-gen HTC devices, it’s built like a tank, and feels like it could withstand some serious abuse (though naturally it’s purdy enough that you’d never want to test that theory). It’s not without fault though; the select and back keys are dangerously close, causing jump-backs from apps a little too frequently. The touch-strip HTC originally envisioned for the Excalibur has been replaced with a touch-sensitive volume keys, which are horrid for in-call use without pulling the phone away from your head. No tactility — no good.

The keyboard, arguably the most important aspect of this device, is so-so. It does have good tactility, but our unit didn’t register all our keypresses when we were typing quickly (and that’s not due to the usual Smartphone two-keys-at-once bug). The spacebar is a bit irksome, as depressing the right side (with our right thumb) would often yield the opposite of what we just mentioned: a space, but no feedback (thus causing us to hit space more than once between words). The addition of AKU3 in this phone gives it XT9 support (which is as useful as it is irritating), as well as hold-down alt keys. The XT9 predictive text engine for QWERTY devices would be welcome if it came with some easy mechanism for turning it on and off, but sadly it does not — this was confirmed with a number of other Dash users. Our Dash’s XT9 would turn on for entering addressees in emails, but would mysteriously turn off when moving to the subject or body fields. Despite a few resets, the problem persisted; it’s impossible to engage and disengage at will, something we’re hoping they’ll fix sooner than later.

On the other hand, hold-down alt keys is a newish feature we can’t live without. Instead of hitting alt and dialing a key to get its alternate character (say, alt-l for $), just hold down l for a sec and $ just shows up. Unless you’re really into typing llllllllllllll… you’ll be happy that now you don’t have to hit that alt key as much. We thought it was a bit of a bummer that the only key to engage the camera is slyly placed to the right of the space bar — not terribly obvious when most devices have side-mounted camera buttons to more quickly and intuitively engage one of the device’s most used features.
(source of this article) http://www.engadget.com/2006/10/11/t-mobile-dash-review/