I don't really like it if it's a real roleplaying game. If you're just having a blast (literally) going from combat to combat, sure.
But rewarding players for things like base jumping from 5 different buildings in one run, emptying 5 clips in one fight and whatever else sounds "cool" pretty much screws the characters that are trying to be professional. Mr. Thrill Seeker will have a lot of fun while Ms. Professional is getting more and more annoyed that she seems to be the only one taking things seriously.
I do like metagame rewards though; things like coming to the table on time and prepared instead of arriving late and then wasting an hour of everyone's time by doing some shopping for your character, helping out a GM with some preparations and such, could be encouraged with some rewards.
Good roleplaying awards too imo.
Ingame stuff could be rewarded with ingame things, but only if they happened spontaneously instead of "because there's a paper that says I get rewarded for doing this". If said basejumper does that stuff in character and manages to make it make sense, get him some extra rep for being such a daredevil or whatever. Emptying 5 clips in a single combat, maybe if your weapons dealer hears about it, he'll give you some extra ammo for the free publicity and extra income he's getting from gangers who think full-auto is the newest rage on the streets. But don't make it some objective that's been carved in stone beforehand...
