I used the ~6" NDS deck drains as well. If I had it to do over again, I would use some square drains spaced apart in the deck instead. The channel drains are a great idea, but what I found is that during the concrete pour they get pushed around a bit, no matter how careful you are and you wind up with un-straight drains. I have about a 38 ft run and a 30 ft run, and one is straight as an arrow, and one has a gentle "bow" in it and it really bugs me aesthetically, though functionally they are fine.