I got one for a cheap phone, so I could practice application development for Android. Since, I've managed to root it, and get that all working, and that's all dandy. I've had it for almost a week, and I can typically find qualms in anything I use in a matter of minutes, so, we'll see...
In terms of the smartphone, it's obviously not going to have as great memory or processing as top-notch phones, but for the price, it's brilliant. With Apps such as SetCPU to overclock it when you're using it (and underclock it when the screen is off), it becomes fairly good.
It also comes with two batteries. One charge to 100% lasted about 2 days, which is to be expected for a smartphone. Do keep in mind this was prior to me making any root changes, so I imagine it'd last considerably longer at its current state.
The material of the back cover is quite a nice (although, some may call it cheap?) texture, so it's a nice ergonomic hold, however, the power/lock button is on the side, making it easy to accidentally press. This is a bit annoying for me, as I've set it to auto-lock when pressed.
The sound from the speakers are clear, and I'm told that my voice is clear on the other end, so I assume that its phone functions are perfectly fine. The phone app is stupidly convoluted to use during a call (Especially when trying to end it), although, that's probably more of a fault with Android as an OS than it is to do with the phone.
It's a great build, and looks nice. The only real bad thing is the TERRIBLE internal memory and the lack of an SD card, so, if you do choose to get this, get at the very least a 4GB microSD to get yourself started.
Overall, if you're looking for an affordable and expandable phone, this is quite a nice choice. Some may see it as basic, but it's Android; you can do whatever you want with it. :}