I use the NP high hook and am a fan.
Helps with floatation for my dodgy water starts and offers good rib protection.
Putting your harness hook through the opening in the front means that the vest stays low when you are in the water. If I have forgotten to clip in the loop at the bottom the vest rides up under your chin.
I would imagine the Whitworths ones would do the same without a strap going through your legs?
Pocket on the front for spares and loops on the back that I can add a small camelback if needed. Had it for 18 months of quite regular use and still looks like new.