the rooms we use have Ampeg STV-3 Pro's in every room, with matching Ampeg cabs, 4x10, 6x10 and 8x10 depending on the room.
personally i've never quite got on with the sound so i take my Barefaced 1x12 and markbass head with me anyway
I've come across some pretty shocking amps in other local rooms though, as well as weird rules, when i was playing guitar in another band i was using an orange tiny terror head and would usually just plug into whichever cab was handy, at one place they had a rule that you weren't allowed to plug your amp into the house cabs so i had to use a Marshall 100w head rather than my little 15w one.