I have started using these on the top of all my snare drums. If you do a lot of rim shots, they are easier on your wrist, and also seem to give you more room for error ensuring you get a clean rim shot every time. I was accurate enough before, and now I am playing in a quieter playing situation, so don't need these features, but this would have come in handy when I was playing more metal.
The BIG difference with these hoops, which is instantly noticeable, is that when playing cross sticking (when the tip of the stick is on the drum head and you knock the shaft of the stick against the rim) the volume is massive. I couldn't believe the difference. I play like this quite a bit and it means that there is less difference in volume between cross sticking and normal playing.
These hoops are stiffer than triple flanged hoops and less stiff than diecast ones. Before I used only triple flanged hoops, as I have found with diecast hoops that you can't compensate for slight irregularities in either the head or the drum in order to get the exact same pitch at each lug. also, because of the additional ridgidity, it means that some lugs are holding less tension and so sometimes bolts work loose. These hoops act as a halfway between both. So while I did not want the extra ridgidity, these hoops are still very tuneable and better than diecast ones. similarly, if you preferred diecast ones, you will still find the qualities you liked in sufficient quantity to be happy with these.
The one disadvantage I have come across (which I overcame bby taping a wooden skewer to the edge of the rim in one place) is that rim mounted microphones won't fit, as there is no ridge to slot onto the bracket (The skewer taped on now slots into the bracket on the microphone so stops it sliding off).
Give them a try- there isn't anything else you can try for 20 quid which will enhance the playing experience as much as these.