There are other forums with discussions about the wifi upgrade. For example one person's mod to add a laptop antenna:


On my C71 the wifi performance is horrible. It is often "no signal" unless I'm within about 3 meters of my access point. Even then the speed is extremely slow.

Other problem is an apparent lack of internal shielding around the backside of the screen, the touchscreen actually detects touches from the back side of the case! Supposedly you can insert something such as paper between the screen and the motherboard to prevent this. The touchscreen is very flaky, especially when the device gets hot.

Screen picture quality is just OK. The viewing angles are really bad. If you look directly at the screen it's not bad. Games using accelerometer are difficult because you can't see the screen if it's tilted...

Front camera is basically useless. It is awful.

Battery life is not great (Maybe 2 hours of non-idle use, charging is not very fast). The device gets very hot if you play games or something intensive like that, too hot to hold sometimes. Zenithink has clocked the CPU to 800MHz max (despite claiming it as 1GHz) and supposedly there is no heat sink on it at all. Overclocking with custom kernels is of course possible, if you want more heat and less runtime.

BTW you can get a fake leather case with a hardware keyboard that fits C71 perfectly, and it's cheap:
http://www.ebay.com/itm/130689353589
I have one and it is quite possibly the worst keyboard I've ever used in my life, but it is better than using an on-screen keyboard, in most cases.

Overall, I'd say it's just kind of "meh". I bought it for around USD$80 last year from Hong Kong. For that price I'm okay with it because I don't expect a miracle. I don't use it for anything serious, just a playground to experiment with Android and play games without needing to reboot my N900.