Any first person thoughts on prodiscus jetpack vs. flak-x?
I personally use a Grip, so I don't have a personal viewpoint, but this is what I've picked up following friends/local players that have used them. Two good videos (The Prodiscus bag is from us):
Prodiscus Bag
Disc Golf Guy's Hyzer Bomb Bag Review
Ultimately I feel that it depends what your main priority is.
The Prodiscus, both the 20+ and the 30+, carry ALOT. You can easily stuff tons of discs in this. I've gotten close to 30 and 40 respectively on each one. It's also very simple and not complex with a million pockets. You have your main compartment, top pocket, sides. In my opinion the Prodiscus is better at carrying big things, like umbrellas and stools. Also I like the putter pocket on top better, it's a bit easier to access and consolidates the putters into one pocket.
The Flak-x, I like because it's really compact and has a nice flow to it. It carries tons of discs, has useful pockets, and it's really versatile and can adapt. You can designate a pocket to be for discs, or for accessories, etc. The other reason I like the Flak-x is because I feel it fits better on my back (I'm a small dude. 5' 7" and 130 lbs). Has a bit more support than the Prodiscus imo. The Flak-x also is better at holding water bottles and such.
There's lots of little differences, that I think the videos cover mostly. In terms of pure size, I think the Prodiscus is the way to go; it carries a ton of discs and stuff, you won't complicate your layout. On the other hand, the Flak-x is more comfortable and is better for the golfer who likes to have a bunch of little accessories as well as being really organized.
Hope this helps.. let me know if I can provide any more details!