This is an independent review of its 4 channel and 9 channel siblings:
Generally speaking they are a bargain. For issues with quality control on such mass produced products, you are best to buy from a local outlet who have a warranty. They are available through mail order outlets like Hobby King but the cost of freight makes return expensive. However if you are already ordering lots of other stuff from them (like cheap servos such as the excellent HXT900) then don't worry too much and get extra receivers for $15! The extensive thread on RCGroups will deal to any queries you may have and fixes for problems.
The range won't be a problem.
See the fix for LiPo protected transmitter batteries on the above thread. Basically they have strangely chosen to run them conventionally on 8 AA cells rather than the correct 5 volts they require.