I had Documents to go on my WinMobile devices and liked it. I just paid for and downloaded the Android version earlier today. I haven't played with it a lot, but so far so good. A bit pricey at $30 but has always served my needs well.
Get the full version of Docs To Go for Android. Quick Office will never have all of the capabilities of Docs To Go. Unfortunately we can't delete QuickOffice because it is stored in ROM. That sucks, but Docs To Go doesn't conflict with QuickOffice.