It really depends on whether you're talking about a real semi-hollow guitar, with alot of acoustic tone, or just something with a chambered body.
A semi hollow will usually have less attack and less sustain, but may have a fatter midrange or a certain kind of resonance that seems to make the notes sound "bigger" at times. The tone would usually be described as warmer or rounder.
A chambered body, something with no "F" holes, that is still relatively solid will yield a very subtle difference at most, but nothing like a true semi-hollow.
Either of them, with the gain set on "kill" thru some hot rod pickups will sound pretty much the same as a solid body.
There may be a feedback issue. A true semi hollow will be a little more prone to feedback, but a chambered body won't, really. Now, if you're talking about a big hollow jazz box or anything like that, it's a different story because the whole top resonates, but with a semi hollow the center of the top is still usually solid.