The super heavy sleeves are basically two sets of the heavy sleeves sewn together and fit much tighter. They are great for doing singles, and maybe all out triples-- but you pretty much have to take them off after every set. So, they are a little unpractical for everyday in my opinion at least. They offer some rebound in the bottom to half way position on your way up, sort of like wraps, but not quite as intense.
The regular heavy sleeves are great, I can leave them on through all of my sets of squats. They make just a bit of difference in the very bottom of your squat, as far as rebound, but hardly any. My knees feel a ton better with them on though and they do a great job keeping the joints warm. If I were to decide between the two, I would go with just the heavy sleeves.
As far as these compared to neoprene, mainly comfort. Neoprene just gets too clamy and sweaty, and they get uncomfortable after awhile for me. The EliteFTS sleeves still keep your knees warm and are more breathable, allowing some of that moisture to escape. Just my experience at least.