Reading up on the Wilson product, looks to be the same kind of device as the zBoost and will have the same installation problems.
Before you buy it, plan on how/where you are going to run at least 25' of coax, and where you will mount the exteranl antenna. They describe an inside window mount, but I can almost guarantee that you won't be happy with the performance if you do that. The transmitter (looks like a wireless router) has to be as far as possible from the external antenna (horizontally and vertically). If they are too close, the transmitter signal will reach the external antenna. If the device senses that the inside transmitter signal is reaching the outside antenna, it reduces power and becomes much less effective (range and signal strength).
Not sure if that makes sense, but I haven't finished my coffee. Follow those installation tips and you'll probably be very happy with either one.