I recently ran into a situation while setting up a UC500 Cisco phone system wherein the client wanted all inbound calls from the PSTN to ring on all phones. Ok, no problem, call blast group takes care of this. Now what was interesting is when they wanted to have a night service that forwarded to the Auto Attendant. Normally a call blast group will not trigger an extension specific event (call forward, etc) but I was pleased to discover that I was able to configure a night service extension and when turned on the UC500 bypassed the callblast and functioned properly.
So far I have been pretty pleased with the UC500 system as an affordable entry level phone system which competes very well with equivalent systems like the Mitel 3300CX.