I'm not really much of an expertise when it comes to compression sleeves or braces, and actually my only other type of brace I've ever used was an Ace knee brace I bought in a supermarket. That said, although I do think this knee brace from CopperJoint is of fairly good quality when it comes to a comfortable sleeve/brace, I gave it 4 stars because of a couple of things:First, it's advertised with an "Anti-Slip System" which I would disagree with. Of course, I should point out before saying anything this could entirely be due to only myself; my quads are actually fairly large. I measured according to the size chart given, and I got a measurement of either 24 or 25 inches, which is an inch or two bigger than the largest size. I did end up buying the largest size (XXL) and although it does fit comfortably, it does not always stay in place, particularly when I'm doing anything out of normal movements (as in walking around the house).To continue, to further emphasize, this could be due to a couple of things that may be due to my own large leg size. Perhaps it's because I cannot pull the sleeve up further than what I desire, which leaves the anti-slip (which I assume is the waved plastic "band" near the top of the sleeve) closer to the knee joint, which is where the majority of the motion is occurring. If I could pull it up further, there is less varying motion happening at it may stay in place better. The opposite argument is that perhaps it's too large - it is comfortable, and I don't feel much of a "compression" effect as I do with other compression clothes I have. If it is supposed to be tighter than what it is currently, then it's possible that compression could help facilitate it staying in place, regardless of where it is.Although I will say again it mostly stays in place doing normal daily things, I have tried to test in others; I've tried sleeping with it on (which is primarily what I bought it for), and I've tried doing a stretching video with it as well. In both cases, the sleeve did not stay on very well. My knees kind of bother me while I try to sleep on occasion, and in that instance where I attempted to where it while sleeping, I woke up with it rolled down below my knee. While I was trying to do my stretching video, again the top of the brace would start to roll down as I was doing the stretching. This obviously does not support the "ensuring your sleeve stays always put, no matter what you do" advertisement the product has in the description.Second, although it's much more minor, I wasn't entirely sure how to wear the thing (or if it even mattered) and there wasn't any kind of real indication in (or on) the package to indicate how to wear it optimally, or if it was even relevant. I figured since the size chart wanted "5 inches above the top of the knee" the top of the sleeve should go around there (and that's what it looks like in the picture). It just seems a little odd to me that the larger portion of the sleeve actually covers more of my calf - at that position, it actually covers around 50% of my calf. Again though, this may not be that relevant, and how much it covers my calf may once more be due to the size I ordered.All in all, it's a good product in terms of being a comfortable sleeve, but it doing exactly what it describes? That remains to be seen. I don't have severe arthritis, soreness, or stiffness; mine kind of comes in waves, and it's just mildly annoying. Does it make that go away? For me, yes it does, but not entirely; the discomfort still lingers a little.So just be warned, results may vary, just like with a lot of other things. Maybe I would like it more (and it would work better) if it was a better fit for me, but I can't say for sure. I will say that I bought it on sale, and that certainly factored into this review - I would be much more disappointed with my purchase if I ended up paying the full (currently) listed price of almost $50.