They handle all the gain that I chuck at them - but I don't play in a band anymore (so I don't know how well the more distorted sounds I meddle with in the living room would cut through), and I only go as far as, say, mid-80s Judas Priest for gain anyway :lol:
From what I've read on here, I have feeling you don't need to go vintage hot, especially not in a semi - but you'll need others with more direct experience...
One thing I have thought since first posting - how bright sounding is your semi? I used to have quite a mellow sounding one years ago - RRs would have been absolutely perfect for me in that one. But I tried a Gibson a while back that had quite a hard/bright accoustic tone, I didn't buy it anyway, but RRs might have sounded a little bright in that one for my tastes.