Just got my droidx yesterday and i'm having some issues, the biggest one appears to be hardware-related. Note, i charged the phone overnight, so battery charge shouldn't be an issue here.
1. Phone shuts off when it's inactive. Not only that, the "on" button doesn't work when trying to turn it back on after it shuts itself off. I have to pull the battery out and back in to get it to power up. This is big and from my research appears to be a very common issue. Note, this doesn't happen all the time, but more often than not. I had to do this every 10 minutes since this morning. It appears to be on now for a good hour which is more than i've ever seen it run since yesterday when i got it.
2. Not all google accounts work when activating your phone. In fact, it's pretty clear that older ones don't work at all. The phone will let you activate w/ an older one but you will not be able to sign into GTalk or download anything from the Market app. I tried 2 gmail accounts both are over 3/4 years old. Neither worked. Created a new one and voila.