This has nothing to do with this thread, but I just felt like ranting. The problem is too many people don't actually compete, so you have all these professional a-hole critics always bashing someone else's style of lifting. What bamazav said is right on. Its all about form and purpose.
No matter what you do you should strive for perfect form. Now from varies based on a persons body type and accommodating leverages and can only be perfected with in the 80+% to be truly of use. Good technique is one that holds through for what ever your purposes are. If your a body builder and do cheat curls but control the top contraction and that is your purpose then your ok. If your not contracting then your not building any muscle your conditioning its fast twitch fibers with speed work.
The bro science goes something like this on the rate from slow to fast: bodybuilding(slow-controlled movements), powerlifting(medium-fast movements), olympic lifting(fast as possible).
Both powerlifting and olympic lifting focus more on acceleration, but being bulky and having static strength still will help in powerlifting, as olympic lifting it is a hinderance.For bodybuilding your focusing on the shape and size of the muscle so everything is primarily contraction work. If you a gym rat then you do what fits your goals.
Same principles with atg squats, wide squats, narrow squats, high bar, low bar, its all variations relative to ones goals. So set your goals first then pick what is most appropriate to them.
Fact of the matter is, anything done right will work, everything done wrong won't.