YES
Subs: Triangles, americanas, kimuras, RNCs, leglocks, gogoplatas, bicep/calf crushers
Transitions: Arm-drags, other ways of taking the back, spider-guard sweeps, shield/93/z-guard sweeps, or anything that keeps their weight off of you.
NO
Subs: omoplatas, armbars from guard, crotch rippers, basically anything they can stop by just posturing or going really heavy
Transitions: most sweeps, again anything they can stop by posturing or going heavy
Mostly I just attack the back and end up with hooks, top position, or a sub in transition. Sweeping is tough, because they are bigger and stronger, so just move around them until they are carrying your weight. For subs, don't lose position for a move that the guy can power out of, or just stop by posturing or going heavy. Play position first, and remember that necks only get so big.