I've taken my family several times (wife and two kids). Find a discount or coupon code to go, then it will be worth it. It is absolute fun for all ages and I recommend you try it out. We always did the hotel/water park combo, but there were people there who stayed at another hotel and just came in for the water park. There's a climate-controlled indoor water park and smaller outdoor park if you want some sunshine. Our rooms were always clean, and the staff was always friendly. The lines for the water slides are long, but they move fast. I have nothing bad to say about the place.
If your kids are little (10 and under), there is a magic wand adventure for them where they basically do a scavenger hunt around the hotel. That will keep them occupied for a few hours. There is also an arcade in the hotel.
My suggestions: don't eat at the hotel restaurant; it is waaay too expensive, and there are plenty of restaurant options in the area. The mall at Concord Mills is nearby and has other things to do, including a Dave and Busters, Sea life, and a movie theatre. Charlotte Motor Speedway is also on that street, if there is an event there when you are. But in all honesty, you will probably just spend the entire time in the water parks at Great Wolf. You'll try every water feature several times.