I've tracked a 5150 cab before and was actually surprised how much I liked the tone. For the conditions we were in, we had a Mesa OS, the 5150 cab and a Behringer cab to choose from. On the 5150II head we tracked, the 5150 cab sounded best. For some reason, the Mesa sounded really bad, but the tracking conditions were FAR from optimal.
Aside from crappy casters and crappy speakers, I think the cab construction itself is pretty decent. I'd throw in some Warehouse veteran 30's over Vintage 30's though, in the interest of money and tone. But I like the Veteran 30's better than Vintage 30's (sweeter, mellower high end, IMO on the Veterans).