I have seen better size AND strength gains with heavier weights on the big compound moves. In order to be able to move heavier and heavier weights, I have progressively moved my rep ranges lower for those exercises. Conversely for isolation moves, I have found that upping the weight into the 3-5 rep range led to a loss of form as I tired quickly. Therefore I tend to stick to 8-12 for isolation work. Strength gains on this style have been great, even whilst cutting, and I'm looking forward to testing it for hypertrophy on the next bulk. Have definitely maintained more muscle mass using this method than I did sticking to higher rep ranges for ALL movements on the previous cut.
There's my two pence/cents