RHINO!
I just bought one CB24-FXO to test for a new customer, and it is completely firmware driven, with an LCD on the front. The only serial control is actually just emulating the front panel and buttons. Out of the box, plug it in, and it auto-detects the T1. Not super-cheap, not over-priced either. And they're all about Asterisk integration solutions. Very personable staff, the engineer who answered my questions by looking at the source code of the firmware was also the guy to write up my order.
The customer is looking to tap onto about 100 analog extensions, and record them programmatically using my software, using Dialogic T1 cards. Rhino is the only one who has a silent monitoring (hi-z) option. Random Adtran sales guy said "Nope" and he didn't ask anyone else.
I went through a bunch of those Zhones... too cheap. The command-line interface was horrible, the digital loggers people kept messing up the orders, sending the wrong units.. sure they were only a couple hundred bucks, but it showed.
