Personally, I think that putting the NovaTac clip anywhere on the light is a bad idea. I put mine on, pulled on it once to see if it had similar springiness to the HDS clip, and immediately bent it. I wouldn't trust a light that cost that much with that clip. They did a good job on the rest of the light, but the clip is trash IMHO.
On my 85P, the bezel leaves no gap when screwed down. The light will not function with the bezel removed. That seems odd to me, but it works fine if the bezel is screwed down tight.