Which one's work best? Are they long enough? Do the work better on wrapless cues? Do they leave any marks when removed?
I know a few people who like and use sleeve grips (aka condoms). A few friends have used the IBS cue grip, a popular grip made from a type of rubber, and have also enjoyed some generic grips they purchased from PoolDawg (could also be IBS for all I know).
I don't know how people do it, I personally can't stand grips or wraps, but to each their own. However, the one sleeve I did like a lot was one made from the same material as some tennis racket grip-tapes (older Wilson tape I think), a medium-blue grippy material with a slightly soft and velvety feel. I have only seen one friend who had one, and he didn't remember where he got it. It felt pretty damn nice.
From what I observed, you can use a sleeve over wrap or wrap-less. I'd be worried about damaging a poorly done linen wrap with a sleeve, but I don't know anybody who has experienced that issue. I suppose because you install it and don't fiddle with it once installed, it should generally be okay, but that is just a guess.
I've seen that a grip can leave a residue that can easily be wiped or cleaned off, and nothing damaging. You may actually need to apply talc to get a sleeve on your cue, so that may leave talc residue in addition.
Anyway, something to be aware of... It seems that depending on your handle diameter and grip material the grips can slip over time as the cue is used, slipping as in moving position on the butt slightly after some use. Usually they only move a bit and finally stick, and not everybody has the problem, but the point is your mileage may vary.
What I really wanted to say is be careful about the grips and your cue case. A friend of mine had a case that his butt fit rather snugly into. He then installed a grip on his butt, and over time the butt got stuck in his case.
My buddy would insert the butt, butt-cap end first, so the handle/grip would slide down to the bottom end of the case (the pin end at the top). Over time the grip developed a slight wrinkle from grabbing the case. It wasn't a big deal as it's rubber and you could smooth it down again. But my friend didn't catch the wrinkle, and then one day he slid the butt into the case and that wrinkled grip bunched-up. In my opinion, I think if he would have inserted the butt pin-end in first, he would not have had this issue.
Once the grip bunched, next time he tried to pull it out, it was stuck. He worked on it for half an hour, and no luck, it was jammed badly. Finally we both pulled on the case/butt, and with all our strength and weight, it took 20 minutes to pull it apart, and we destroyed the case doing it. It literally chewed-up the inside of the case, bursting the tube, and rupturing the covering.
So if you get a grip, make sure it doesn't snag or hang-up in the case, and make sure that if it does, fix it before it becomes a big problem. He still liked the grip so much that he bought a new case and a new replacement grip.