I've had my DW 14.4 for nearly 10 years. The drill itself is great and has survived a night in a bucket of water (some idiot left the valve open on the garden hose in his garage). I've never had a power issue with it.
However, I did have a problem with the charger/batteries about 3 years ago. The charger blew out both batteries in a messy little battery explosion. I think it had something to do with the wall outlet it was plugged into since I'm still lusing the charger with a new battery but I was still disappointed the charger didn't have a fail safe.
My biggest problem with the batteries is the cost. I still haven't replaced the back up battery because I find it hard to justify the extra $70 or so for it. I would buy another in a second though.