For the price, this is pretty decent. I've had it for 6 months now. I use it for my Blackberry Tour, and my 60GB Creative Zen Vison M. Initially it was a tight fit, I had to stretch it out a bit by putting in my Zen, and putting some cardboard behind it--it appears to be actual leather so it does stretch. It fits fine now. However, it's still not real easy to use the buttons on my Zen when it's in the holder. Another problem is that the "velcro" is not very sticky. I replaced it with better holding velcro that I got from the local arts and crafts store. And the plastic pieces that the adjustable arm band fits through tend to twist sideways when tightened. There are no holes on the side to plug in headphones to my BlackBerry, but I usually just put it on speaker and run in the country w/o headphones--works great for that. The stitching on it seems very durable though, even with all the stretching I did on it, it didn't blow out a seam or anything.
All it all, it's good for the price. Not perfect, but it meets my needs and it's holding up much better than I expected.