Lanc does carry the mostest, but like you said, poor defensive armament. Got to survive over target to do some good. All other bombers faster to altitude and target than the Lanc is. And I prefer to land kills in other bombers, than bomb and bail (or burn) in a Lanc.
Most Lancs I see dropping ord are using a shotgun method, sometimes level, sometimes diving.... which is a waste of ord considering how accurate bombing can be done in the war arenas.
Consider your target, the bomb load you will need for it, and select the plane.
I tend to run B-17's with 500 #'s these days to go after strats from altitude (10K up to 25K, single salvo), but still able to drop a hangar with salvo 2 or 3, or hit a town, if needed.
If I'm actually going after hangars, or HQ , as part of larger mission, then it's the B-24's with 1K's.
Killing a CV, I'll lift Ki-67's with 8-100kg eggs or a flight of Ar234's with 3-500kgs or even JU-88's just for fun. (and Ki-61 makes a good dive bomber with it's 2-250kg bombs for a small group, and can fight afterwards well enough.)
Going after GV's... B-26's with 500 #'s. Or JU-88's if we control the sky.
Knocking out radar towers or ord at many bases, Ki-67's with 8-100kg's again, or 15-50kgs with salvo 2. Nice penetration bomber.
Trying to level a strat factory with not too high chance of being intercepted, JU-88's with max bomb load.
There are more options than Lanc or B24.