I always use quality products, even in residential I use commercial grade. For a few extra bucks its worth it. As far as workmanship goes I don't cut corners, its just not worth it. Besides, some of the work I do is repairng/replacing crappy work done by someone else. I just changed a panel out (upgraded from 125a to 200a) and the 2" pvc conduit feeding up to the panel came apart in the wall because some jackass used black abs couplings which are shorter than the grey ones we use and the glue was some white stuff that just came apart. It was a pain in the butt to fix.
