We purchased one of these Athalon bags, tried it out for a short trip, and liked it so much that we purchased another one.  They are very sturdily designed and made.  We then took both of these bags on a long trip and the amount that can be packed into one of these is amazing.  When fully stuffed, the bag still looks surprisingly trim on the outside, without any noticeable bulges.  I appreciated this bag so much that I took an inventory of one bag when unpacking at home, to share on this review.  Granted, the bag was packed to use all available space. The contents of ONE of these bags was as follows:

1 set Tilos travel snorkeling fins (about 20")
2 snorkeling masks with cases
1 snorkel
3 pr. neoprene flipper socks
3 pr. neoprene diving gloves
1 diving hood
1 lycra suit for snorkeling, 3XL
1 Speedo mesh backback
1 Dry Pak drypouch
1 pr. mens sturdy sandals sz. 13
2 mens swim trunks
1 boys XL swim trunks
1 women's one-piece swimsuit
4 hats
1 pr. mens shorts
1 pr. mens cotton sweatpants
1 mens collared shirt XL
1 mens polo shirt XXL
8 mens t-shirts XXL
2 mens t-shirts S
4 pr. underwear
1 rain poncho
1 ziplock bag laundry soap
2 razors
1 deck cards
1 med. size book
1 bag seashells/rocks
1 rock - 2 lbs

Quite a lot of stuff!  Lastly, one reviewer felt that the telescoping handle was too short, but we did not notice any problem with that at all, and we are tall people, 5'11" and 6'1" barefoot. The only negative was that the handles don't snap firmly into place when closed, but they stayed put when closed and it didn't present any problems.  We decided to get the green color, and ours is not as bright as it appears in the photo. It made the bag easy to spot at the airport.  This bag also has good hand grips in unexpected places, so it was easy to put in the overhead bin on the plane, and it fit easily, too.  It is a little narrower toward the top, which could help it fit in a plane with smaller overhead bins.  An added plus are the buckling straps which take any strain off of the zipper.  Not only do we appreciate these Athalon bags, we have a lot of respect for them, too.  Bravo, Athalon!