Depnds on the job. For new work I use metal and drive sheetrock screws with a cordless drill. On old work I like Allied molded boxes because I can trim the wing when dealing with plaster and lath walls. I never cared much for the clips that I used to use on the metal boxes, just worried me the they came so close to the receptacle screws. Also have bad memories from working where we used MC and metal boxes with clips and upon powering the circuit having a brief 4 of July only to discover the receptacle had grounded on the clip because it bowed out too much.
