Depends on your thinking, lighter is better, or heavier hardware is better?
Heavy weight drums don't specifically equate to quality... ask GURU.
The reason there's less material in the SC lug is simply to save on costs.
For me the overall weight of the SC kit is a plus (84lbs-5 shells, tom holders and FT legs). My MAPLE CUSTOM 5 piece is 'heavy' compared too and IMO the quality of sound from STAGE CUSTOM is just as usable, and maybe even more so, the thick MAPLE CUSTOM BD doesn't sound as good as the lighter SC IMO, and thicker/heavier toms are too loud for some applications, they require restraint and that's an aspect of drumming you don't want to be a slave to the whole night at a gig.
The SC BD spurs are a much better design than what's on YAMAHA'S higher line kits too, they're easier to open/close and very doubtful I'd ever break one. I've broken a MAPLE CUSTOM BD spur, that design is the 'only' YAMAHA hardware piece I don't care for. I've complained to YAMAHA in the past about it.
IMO the STAGE CUSTOM design spur is superior in every way, the only improvement I'd like to see on it is like what GRETSCH has on their BD spurs, finger operated screws for the height adjustment, so nice being able to adjust the height of your BD spurs w/o a drum key.