Big difference in price...worth the extra money for the Ortofons when considering sound, comfort, dependability and cable strength?
I can't speak to the R-50's, but the EQ-5's are quite good in my opinion.
I picked up a pair last year (many months ago) on the FS forum for under $200, and I think I even saw a pair on there for $160 recently. At that price I would recommend them as a nice option. I was a bit worried about the cable, but Ive had no problems thus far.
I've been out jogging with mine and I had no problems at all and they sound better than the R-50, now they don't blow them away or anything but they do have a better over all sound imo. Both have about the same amount of detail and an above average soundstage but the e-Q5's soundstage is quite a bit larger sounding with a more airy feel and the bass impact and depth is better as well. They're also very comfortable, I've used them for about 6 hours straight with no discomfort at all.