I've had some 661 evo d30 elbow pads since early last year. I think they are great for elbow pads, very very flexible, dont know your wearing them an all that, whislt giving suprising protection, as tested out with a big hammer 8O. Dont slip down and certainly dont restrict arm movment at all, unlike the veggie wings i tryed, my god they were rubbish.
Couple of offs at lee quary, cant say weather the elbow pads took any really big hits, but I've been unscathed on all ocasions, so they may have just done the job properly.
That said, I couldnt justify the cost for the evo knee pads, and went with the kyle straits for my legs. That joint articulates a lot less than the elbows, and I recon knees are subject to more impact force where the hard shell wont impeed movment as much and offer more protection.