I can't stand going to the gym and seeing guys with horrible lifting form, usually brought on by the desire to handle heavier weights...either in an effort to look cool, or the misguided attempt to get bigger!
Putting aside the use of "controlled cheating," a real technique that when used properly can extend a set "beyond failure," cheating during your exercises is only taking the load OFF OF your target muscle and placing it onto your tendons and ligaments.
Please, if you want to get huge, lift with a complete range of motion, control the negative, and focus on the muscle you intend on working. If this means lowering your poundages a bit, than DO IT!!! Eventually, you will be back up to your former weights, and you'll be carrying a hell of alot more muscle.
I'm much more impressed seeing someone squat 275 for 10 reps to rock bottom, than someone squat 455 for 10 meaningless quarter reps!
LIFT STRICT AND GGGRRROOOWWWW!!!!!!