I had been told that they are affiliated with one of the Pentecostal denominations although you would want to verify that.
If you are wanting a non-denominational church (but contemporary) you might want to give Connections Church ---
Raleigh Churches - Non-denominational: Connections Church - Raleigh, Cary, Apex a try. Our services last just about an hour -- the pastor is very gifted so you often wish his messages were even longer. The atmosphere is casual and welcoming. You can check out a 2 minute video on the website which shows the style of our teaching.
By all means, check out Grace Church if it is what you are looking for.