i currently own a DC720 and it is really weak. can barely drill a regular bit hole through a 2x lumber but it takes forever to do it with a speedbore.
i was wondering how much better the 920 (XRP) is ? it sure looks more heavy-duty, metal chuck and all that. but the power metrics on the dewalt site compared only 410 for 720 vs 480 for 920 - i need more than 20% stronger.
every electrical contractor ive worked for uses 18 volt xrp drills from dewalt. They are great drills. I think there are better values out there. But if your sparing no expense, dewalt is a great drill. It sounds like either your batteries are shot, or you are overworking your drill and burned the motor up