If it's a gloss finish there is some truth to that, if it's a flat finish, sadly, what you spray is what you get. The second you try buffing a flat finish it's going to gloss up.

As for gloss finishes:

Buffing will only remove surface scratches. If you want to get rid of orange peel, dust spots, runs etc, well, elbow grease is needed. I typically go the good old tried and true method of wet sanding with 2000 grit paper first. This is of course assuming your finish sprayed out nice and flat. If it's really orange peeled, you can start with 1500 grit. If you start with 1500, get it all level, get rid of runs, dust, etc. You have to use a block, but use a hard foam pad, so that it still follows curves and such. Once done with the 1500, go to 2000 and sand until ALL the 1500 scratches are gone. From this point you have a couple options, one is to continue sanding with progressively finer grits, 2500 and then 3000. Or, you can start buffing using a cutting compound. BUT!!!!!!!! Be extremelly careful with an cutting compounds, you will go through your clear on edges in seconds. Particularly on a model where we usually only put 2 or 3 coats of clear on and they are light thin coats to boot. So, lets assume the safe route and sand out to 3000. At that point you can use a fine polishing compound. I use an orbital buffer, if you clamp it to the workbench you can hold your model parts and that lessens the chance of them getting flung across the room. You can buff it out by hand, but that's a huge amount of work, though it is safer if you're not comfortable using the power buffer. After that it should be glowing pretty good, but go over it again with a swirl remover and WOW, it will look 10 feet deep.
As for pads, I use Meguiars foam pads, I use the 9000 pads for both the fine cut and the swirl remover, I use 8000 if I use a medium cut compound.

There is also a newer system out there for sanding that I have just started using called the trizak (don't know if that's spelled correctly) system. This starts out by wetsanding with 1500 on an orbital, then going to a 3000 grit pad on the orbital. It goes very quickly, then you buff the same way. The downside to this system is it is quite expensive, about $160 for 10 of the 3000 grit pads. It will take about 4 pads to do a jet the size of a bandit IF you don't hit edges with it, if you do hit edges they wear out faster. But of course, as with any system using power, you can go through a corner much faster as well.