I've had my microcell for a little over a year, and at this point it is disconnected because as bad as cell service is without it, it's way better than service with it.  Lot's of problems with outgoiing calls failing, and at this point, outgoing voice quality is so choppy on so many calls that are connected, it is useless.  AT&T support has got to be about the worst there is.  Really good at saying "Thank You" and "I'm Sorry", but solutions are not part of the program. 

What's the best way to avoid microcell problems?  Don't buy one.