I currently have the T-Mobile MDA. Bought it around 2 months ago, but the screen is already busted - apart from the 4 corners of the screen, it isn't a touchscreen anymore

Since the phone is still under warranty from T-Mobile, I can:

a. Replace with another MDA
b. Replace with Sidekick
c. Replace with Dash

From the reviews and comments here on FT and other websites, Dash seems to be the better phone. The only reason I picked the MDA was that I liked the full keypad, but I can certainly live with a less bulky phone...

For those who've used all three phones, which phone would you recommend? Sync with my Exchange server is the ONLY requirement, and I know that MDA and Dash are supported (haven't inquired about Sidekick)...

Thanks in advance.

If you need to sync with Exchange, I'd stay away from the SK.

We have one of each in the house (Dash, MDA and SK). It comes down to personal preference.

MDA: Touch screen, better keyboard, 3G, more apps (Windows Terminal Svcs client, for example).
Dash: Smaller & lighter, WM6 now (dk about the MDA) better voice (IMHO).