Knee braces: any suggestions?

Has anyone used either a DonJoy or Breg knee brace for knee instability?

I'm meaning specifically knee braces as opposed to tight knee pads.

Eg/
http://www.youtube.com/watch?v=AZ7_ZRkeG4w


Are there any brands / models that are good for groundwork? Ideally, there'd be something that protect my knee but doesn't hurt my partner

I had a Don Joy when I played lacrosee. It was a good knee brace but not one that I think I could roll with. I use Mizuno baseball sliding shin pads and they work great.

Are the Don Joy braces too bulky? Some of them look not too bad, but without seeing in IRL...

I would have though putting a neoprene sleeve over the top of something like this would be ok?

http://www.youtube.com/watch?v=MWZQQWUnVjg

Of course, not being able to try one in person before buying it kinda limits my opinion

The one I had was very bulky and a hard material. I couldn't imagine throwing up a high guard without smacking my training partner in the head. Maybe they've changed.

training partners don't seem to care for them much.

I figure a kneepad over the top would cushion and sharp edges.

Has anyone used any braces they can recommend? How about one like this

http://www.braceshop.com/productcart/pc/DonJoy-Drytex-Hinged-Knee-Brace-638p262.htm

I can't tell whether it has rigid supports in it (medial and lateral) but it seems to have some kind of adjustment dial

I use BioSkin supports for my elbows. Not bulky at all. Phone Post

Alright I have had almost any and every knee brace there is because I have terrible knees(3 acl replacements). Honestly you shouldn't go with anything hinged in Jiu Jitsu because regardless of having it covered it is still going to be hard and hurt someone if you hit them with it. I just buy the latex compression sleeves and they do the job, not as much support but they allow almost the full range of movement and will not hurt anyone.