I've always enjoyed the idea of faction locked gear. It gives the factions a little bit more life and variance.
Apb as is though, doesn't have a lot of things that can be locked between factions aside from some cars.
Obviously, weapons aren't a good idea because of balancing reasons, but if for some reason the weapons get reworked, or new weapons come out, I'd be okay with seeing some kind of faction specific gear, within reason of course.
I just feel like a little bit of variety and flair for each faction could help give them the credance towards their inherent differences.
I.E. more neat tacitcal cop stuff for cops and more neat jerry-rigged crim stuff for crims.
Or something along those lines.