I bought the AW Undershorts: I play Underwater Rugby, so there is definitely lots of fast swimming, tackling etc. The problem I faced with other companies' Awrah covering shorts was that the part of the fabric which covers the navel used to succumb easily to water resistance while swimming fast: It used to fold/roll down, uncovering my Navel area. The extremely sturdy and wide elastic band not only holds that part of the fabric in place in all that rough and tumble, but it also doesn't let that part of the fabric roll down uncovering your Awrah which is great. It doesn't limit my movement in any way, and it feels extremely comfortable.
Another great thing is: Other companies that I know of, at the time of writing this review, sell awrah covering swim shorts that you can't separate from the inner fabric. So I essentially save money, because I can combine the AW Undershorts with all of my “western” shorter swim shorts, that don't cover my Awrah.
May Allah bless the designers and manufacturers of this product. This is truly one of the products which I am extremely happy about.