I generally only request cabinets when I'm on tour these days. Since I signed with TC electronics I carry my amp with me wherever I go, and just need cabs when I get to a new city.
TC cabs aren't available everywhere just yet so some of the smaller markets in the world end up providing different brands for backline, but the head is with me so my sound is very consistent.
I ran into some terrible gear on the road in Wyoming a few weeks ago, and they just had nothing there at all cos it was in the middle of nowhere. You just get on with the gig and make the best of it, cos you'll just get too stressed out otherwise.
Janek