I've only had this for a few days, but have found the wireless reception to be very weak, so it doesn't stay online in areas of my house that have good reception on our Mac minis or Asus EEE netbooks. Apparently, this is caused by the auto-update to Android 3.2, but should be fixed.
The other problem is the large number of intrusive and unwanted programs (excess media players and games), which seem to start up on their own even if you don't use them, and which cannot be uninstalled. One of these, a media player with a blue screen and three big icons for movies, photos, and music, wakes up quite often and takes over the device, even if you are not playing any music or videos. To make the tablet usable, you have to go to the system screen to kill these each time I start up the tablet, very annoying.
Why does Acer have to impose their bloated software on your computer, without giving you the option to remove them?
Finally, it's very locked-down, meaning that you can't really install programs outside of the app store paradigm. It's not really a computer, just a media consumption device. This is probably an issue with Android rather than Acer, but it's a disappointment.
The tablet is also a bit heavier than I expected, but otherwise okay as these tablets go. I wish I'd tried out the Asus Transformer or Galaxy before buying, however.