Im quite surprised that there was such a dramatic difference between the Les Pauls and the SG. The specs of both guitars are generally pretty close, is the tonal difference basically down to the maple top?
The specs are actually not _that_ close. Yes, there's the maple top and it make quite a big difference by itself, but there's also the shape, mass, thickness etc... In fact there are more differences between a LP and a SG than between a Strat and a Tele, and the difference between a Strat and Tele is not only about bridge and pups.
And, well.... My own experience with SGs is that it's a very "emotionally disturbed", unpredictable kind of guitar :lol:. It usually seems works fine with 1/ brighter low output pups, 2/ P90, and 3/ very high, preferably ceramic pups. Anything else is really a "hit or miss" affair, and really depends on the exact guitar and pup. Now don't ask me why - I've tried brighter SGs that did sound muddy with mid/hi output alnico pups, I don't understand why mine doesn't react the same way (but I'm glad it does)...