I usually keep it 4-8. Maybe a couple of burn out sets to 12. No problems with strength, but a lot of the biggest guys I've known do 6-8 sets of 15+.
It this unique to their genetics, or are high reps the way to go for size? For example, on leg day, I'm thinking of dropping the 8 sets of 4-6 on squats and doing 8 sets of 15+ on hacks.
Would this be a good move?