Hmmm, I've not had any direct experience with the cabs, but the rumble combos appear to be cheap for a reason as far as I can tell. Ok sound, but poor build quality.
Wish I could help more.
Personally, I reckon you'd be better off hanging around on this site for a while waiting for a second hand Hartke or Trace cab. They come up occasionally for really good value.
Truckstop