Hey - I've had a great experience with Phoenix and agree with both other posts above.
One thing you have there is that neither of the guys (even the third guy that works p/t) are hour building - they are fantastic instructors. I'm not sure there is an issue with weekend bookings - I reckon fine if you book at the time of your last lesson - you really want quality, not quantity!
It very much is a question of finding the place that works best for you - I would do a trial everywhere within your driving range and go with where works.
Have fun!!!