Battlefield bad company 2 cles?

so yeah this is targeted towards the people that have bought and played the new battlefield game fairly extensively. so ive been trying to decide on one cl that would be my main cl because its alot easier to unlock stuff if you try to stick to one thing, so ive pretty much narrowed it down to engineer or recon, i have like 10k exp on both but im not sure which one to continue with, which do you guys think i should use?