It's still not super fast, but you can get certs pretty quick if you get with a good galaxy crew. Hopping from base to base capturing small bases, and when you hit a big base you can usually get into some pretty good fights where you can rake in thousands pretty quick from all the kills.
I've been enjoying playing Medic lately. Their rifle is really nice, I get lots of kills with it. And healing/resing people is rewarded with points. 75 for resing, 10 for healing a certain amount. Running around with a big group reviving and healing people in between skirmishes where you pull off a few kills each time can add up pretty quick. You get bonus points if you're in a squad with the people you're healing too, so if you can get in a good 12 man squad it's even better.
I was with a nice group the other day with 3 engineers, 6 heavies, and 3 medics (including me). At one point a lib and 5 tanks (2 lightnings and 3 magriders) came in blew our galaxy and nearly wiped us out, killing both the other medics and most everyone else and losing one lightning and one magrider in the process. I raised both the medics and we started picking up all the heavies, and soon they were blasting the tanks to bits while us medics kept them revived and healed up. Two of the engineers dropped ammo packs for them to have more rockets too. It was crazy - basically open ground, with me and the other two medics racing around reviving and healing people while the heavies danced around popping off rockets at the tanks. I died once but got raised by one of the other medics almost instantly, popped my heal on, and kept reviving others. Meanwhile one of the engineers respawned at the gate and arrived with our new galaxy just as we captured the facility, and we immediately flew right off to the next objective. We killed all the tanks and dozens of infantry by the time we were done (not sure what happened to the lib, it just bombed the gal and flew off).
Wish I could get in full coordinated groups like that every time I play the game. That's why we need to get organized into one outfit, so we can set that kind of stuff up on a regular basis
I still kind of want to unlock the resurrection grenades. I've seen medics turn a fight around by dropping one of those on top of a group of dead guys.