Ahhh the innocence of youth. Wait 'till you've been lifting for 10 years or so then you'll understand. Most people on the over35 forum seem to use them.
Whether you get any strength carryover from them is debatable but they definitely help my old knees by keeping them warm during lifting. They are nothing like knee wraps.
As far as I know sleeves are legal in all feds including RAW.
I had some neoprene ones that kept my knees really warm but the stitching didn't last 2 months. My current ones are from strengthshop and I would recommend them.