Our we the only ones installing these?
My experience so far:
The redundancy seems to work great. The PI is a lot more friendly then CVD although I am still a fan of command line. Converting IPX to gateways is simple and a good cost savings on upgrading.
That's the pros, as to the cons.
DID handling is the worst I've ever seen. If you are dealing with less than 200 or have the luxury of matching DID to extension, it is tolerable. I routinely deal with over a 1000 DIDs and the programming is ridiculous.
On MOH, from the web I get the feeling a lot of the new IP solutions are moving to WAV files which is ok, but I have a lot of customers still what some kind of stream capabilities. And to have to reset the hold system to chance the music/message is unacceptable. I deal with security central stations. This is life and death phone calls. They can't be down 5 minutes just to change the MOH.
The labeling of calls that made the IPX so nice is not available. Where we used to be able to label a DID through out the system and pop a name on the phones display as to which DID the call came in on is gone. I am not sure rather to blame Tadiran or SIP in general, but I miss the labels.

Those are my complaints off the top of my head. I was just trying to get a feel for what my fellow techs thought.

Never blame on malice, what can be adequately attributed to STUPIDITY!!