I've used these on and off over the years. They're good for adding extra grip, and also reducing the concave shape of the 360 analog sticks (thereby helping aim). I've seen some MLG pro players swear by these.
They don't add much height at all to your analog stick, so they're not like FPS Freeks. FPS Freeks decrease the mechanical resistance of analog sticks by increasing mechanical leverage via extra length, and also adding range of motion (analog stick travel). All these Grip-it's do is add a different feel to the analog sticks. Some may like the feel, some may hate it. For $4, they're worth giving a try.
Anyway, $4 is a pretty good price. They used to be a few dollars more expensive.
[quote name='affa']i second that they fall off of ps3 controllers too easily. i have a pile of them, and i LOVE them... except they fall off quite a bit to the point of being quite annoying. this happens mostly in games that you slide hard in, like, say, dual stick shooters (where you're putting a lot of horizontal pressure on them.[/QUOTE]
You guys must be abusing the hell out of your PS3 analog sticks. I've used any combination of FPS Freeks, Grip-it's, Orb grips, Modsticks, and pretty much everything else you can think of. I've never had the problem of Grip-it's slipping off of my PS3 controller. They wrap around your analog stick pretty tight. Like an undersized condom.