I'm a picky customer, and so I tend to research things prior to purchase. I did so in this case and in the process stumbled upon the KingKong Plus 45 Duffel Bag. I'm so glad I did. My expectations were high, and this bag has exceeded all of them.
I've used the bag for trips to the gym for about a month now, and it has been (just as advertised) quite good.
It appears likely to prove to be durable, which is important to me. It also appears to be well designed. The myriad pockets help me keep all my "stuff" organized.
Minor caveat: I have not yet needed to use the "shoe tunnel" storage (for I have a locker at the gym). However, when I eventually do, I expect the bag to fill that function nicely.
Initially, this gym bag seemed a bit pricey, but I deem it to represent excellent value. I look forward to using it for many years to come.
This is a STRONG recommendation.