MGCP in VoIP

Is anyone, who is using MGCP signallization in your VoIP gateways and softswitch? After many tests with putting VoIP with MGCP signallization in Higher Priority band, I don’t know is the problem in using MGCP instead of SIP?
Maybe somebody have some information of differences in using MGCP and SIP?

Thanks for reading this and answering.

Krzysiek - ptysiek