I generally agree with pumpster, but at the same time your building the body by using progressive overload and that can come from different techniques.. ie. heavier weight, more reps, forced reps ect.. AS long as you don't give yourself a chance to adapt and plateau you'll be growing.
I was referring to the general question about rep ranges. Progressive overload can be done in many ways-rep range/weight, time between sets and the use of intensity techniques that either combine the first two and/or add cheats, forced reps, etc.
With all those options, IMO it's unnecessary to venture into low reps/heavier weight territory, which is just another combination of same, but with the added downsides of less effective growth potential coupled with greater injury potential. It's easier to generate shocks through other means.
If you want to play with rep range & weight, do it between moderate to high reps, avoiding low reps. The only exceptions i can see are where the muscle's already fatigued & warmed by previous work and shorter rests. ie 5 x 5 with short rests of 15-45 seconds between sets. Or low reps right after a previous set of higher reps. In either case the weight used for lower reps won't be as high due to exhaustion, and the muscle's already warm.