It should be the same sound-wise.
The only things one needs to consider when discussing combos vs. seperates is...
1. Portability. Can you carry the seperates easier than the combo? Some think one heavy trip is better than two lighter trips. Something to consider if you can't park close to where you are hauling it or you play places with a lot of stairs.
2. Extra Cabs. Can the combo handle extension cabs, and if so, at what ohms? Some can, some can't, or not very well. With seperates, you can replace components easier.
3. Power. Is the combo in question powerful enough on it's own to handle a variety of situations, and if not see no. 2.
Combos, in and of themselves, were designed to be an all in one unit. If you want to be able to change things up, some combos allow for heads to be pulled out and replaced by a different head...ala Carvin RC210. Some don't.
Overall, I like combos, but only ones where I can add an extension cab if need be. There's a wide variety of good ones out there.
