Doesn't bounce around.
Is comfortable and acts like a kidney belt.
I my pack used on EBay for a great price and couldn't be happier. I've tried other belt type packs and was never happy with them.
The kidney belt style really helps keep the pack from being sloppy. It tucks in nicely on your back and actually helps my lower back from getting sore. (Yes, at 31 I'm an old fart compared to most of the paintball community)
It has elastic at the top of each pod holder which pushes the pods into your hand when you release the elastic. I thought this was a gimmick and didn't think it had much value until I used a friend's rec pack. Turns out it makes a big difference getting to your pods. Especially when you're pinned down and don't have much time to reload.
On my particular pack I had a seam rip loose. I doubt it is common with these, but I thought it should be mentioned. A little bit of restitching and it should be fine.
The NXE 4 pod pro pack is a fantastic pod holder. It doesn't bounce around like cheaper packs are prone to do and it virtually fires the pods into your hand. Pick one up, you won't be sorry (especially if you can find a used one cheap).