We use Medware (now Sage or even something else). Have used since 1996 -- started as a DOS program, now it runs on my server in SBS Essentials.
Staff is used to it, it has been rock solid, and support has been good, despite some comments to the contrary on this board.
There is no interface with AC -- in some ways this is a blessing, since when AC goes into a tailspin, as it does from time to time, we can still function as scheduling and billing is done by Medware (and Office Ally for electronic billing.) There is some duplication of effort in having two programs, but it seems to be pretty easy for the staff to work out.
I do my own coding, my wife relies on our in-house biller. Doesn't seem to make much difference. We don't get any rejections for inappropriate codes, and so far as I can tell, don't get downcoded.
