Own a knighthawk. Only use it in the tropics, and never inflate it unless I have to. It forces your face down on the surface, and the wings create a lot of drag. I used it for hundreds of dives and spent too much on it to buy another. Last weekend I borrowed a cobbled together aluminum backplate with attached side wings and absolutely loved it. Got so excited I forgot the name of the stuff, I think it was from DiveRite(?) or Hollis.
The knighthawk is good, but if I did it over I would build up a custom rig for about a 1/3 the price. Mine has an Air2, which I would eliminate as well. It's a waste of money. I had to use it a couple of times for airshare, and the breathing from the Air2 is not the best. As I panic, I will hit the inflate button while trying to keep the mouthpiece in. With all the pockets, zippers and mesh bags that suddenly appear and get in the way, it's hard to dump air. I'll take the mouthpiece out and use the breathing hose to dump.. But I digress
The knighthawk is good, but if I did it over I would build up a custom rig for about a 1/3 the price. Mine has an Air2, which I would eliminate as well. It's a waste of money. I had to use it a couple of times for airshare, and the breathing from the Air2 is not the best. As I panic, I will hit the inflate button while trying to keep the mouthpiece in. With all the pockets, zippers and mesh bags that suddenly appear and get in the way, it's hard to dump air. I'll take the mouthpiece out and use the breathing hose to dump.. But I digress