I've had both DYE and Eclipse elbow pads, both are great and I would recommend them to anyone, but here are some pro/cons to each one in my opinion.
DYE products tend to cost a bit more, but it's still a great product. The season I use DYE arm guards, they are very rugged and can take quite the beating. Ventilation seemed on par with any other elbow pads I've tried. You can play in just a T-shirt and these elbow pads and not worry about ripping them up. Very rugged material. The only thing I dislike about the DYE arm guards is that the part that goes over your elbow has a bunch of plastic/rubber 'bumps,' I guess perhaps for grip? Or maybe so your jersey doesn't slide around so much, or something. But to me, this doesn't help to much as for a bounce factor. That's the only bit I dislike, everything else about them is awesome!
Eclipse arm guards, these are also great pads. Plenty of padding along the forearms and elbow. These have less hard surface material than the DYE arm guards, but there is that rubber logo near the wrist, not going to get many bounces there. The thing I dislike about these arm guards is that the material it is made out of does not seem as durable as the stuff DYE uses. These pads I've always "babied" when I play. I always wore a jersey or longsleeve when I wore these pads. The material feels similar to an under armor shirt, something like that. Ventilation again is on par with other pads. So other than the material being less durable than DYE's, you just have to wear a longsleeve or jersey to help protect and make them last longer. Still great pads.