One thing with pop-up rigs, I think that the hooking mechanics are often different from bottom bait rigs (including snowman baits), because the carp may not be sucking, but mouthing the bait. They may suck the whole lot in, but a longer hair could see them not taking in the hook.
I know Brian Garner and Bill Cottam did have success on long haired pop-ups on The Mangrove though.
The Spinner and 360 rigs, or even any hinged pop-up rig should guarantee bottom lip hooking. I have had occasional top lip hook-ups with a straight through stiffer hooklink material, where I'm convinced the carp has closed its mouth over the pop-up facing away from me, I.e it is between the rod tip and the bait.