The R.E.D. Rail guard is the best I have used. It uses a seperate knee and shin guard that lets your knees move freely. Also provides really good protection without being insanely bulky.
However, out of those two I would use the Protect IPS rail guard as this was my knee/shin guard before the reds.
Ahh, didn't even notice these ones! It got a minus one star b/c of the velco catching on to the inner linings of your pants if they have fleece.
I like the fact that they are separated too!
So between the Red vs Protec, which one would you recommend?