It doesn't really matter to me (wasn't a choice in the poll).
I've seen some cheesy (cheap feeling) buttons on a couple of devices, and some that were quite small (making them hard to use). When comparing devices, I ended up going with the Mesmerize without any hard buttons.
The only issue I have with the soft buttons is having to guess where each button actually is when it is dark. Once they light up, I'm fine. If there was a small bump in between each button, it would make it a lot easier to find, though.