As far as processing power, you get a a lot. It may not be very quick, but everything from the Android market should work on this phone, so getting apps isn't an issue. The other cool feature is that it automatically switches fromn 3G (yes, it's only 3G) to wifi and vice versa based on availability. It has limited customization, five screens for apps and shortcuts. The major part of customizing is the Sprint iD which unlocks tons of apps and wallpapers, although it is a bit difficult to use. It is a strong phone, so it can withstand water (within reason), droppings, and pretty much anything else (better with a case).
The minor bugs include when there are notifications of sprint app deals, but it will always lead to the home screen, so that gets annoying, the other major thing which seems to be a problem with many phones is that if you get an email notifications it will appear as both a Gmail app and email app notification for the same emails, although that can be fixed. The finall minor issue I encountered was the lower volume button getting increasing the dificult to
Some tips: get a screen protector because the screen by itself is fragile. A case is not necessary although you couldn't find one anyway. It would also be good to not mess with the extremities, because they will fall off. So, the Sanyo Zio is overall a solid phone that proves that there still is a place for smaller phone makers in today's market.