I get about the same signal as your family has, and my SPC has great service in my home. I wish they would mass advertise these things. They are a great technology.
The Sprint Phone Connect 2, which replaced the model I have, has had great reviews so far, and even uses EVDO. How they are using it for voice is beyond me, as I thought EVDO was data only, but it still won't work for faxing.