I must admit that the Sport Loop has won me over. At first I was kind of underwhelmed by it. My S4 came with the seashell (light gray) sport loop. I thought it looked nice for a fabric band, but I was concerned that the velcro wouldn't be secure enough, or that it would pull at the fabric and cause it to fray and wear prematurely. I was also worried other things catching on the loop fabric. It has been my most frequently worn watch band of the last 4 months, and still looks new and holds securely. I just keep going back to it because it is so comfortable. My other watch bands are the sport band that came with my S0, a knockoff leather loop (because Apple refuses to make a 38/40mm size), a knockoff woven nylon, and a third party leather strap.
I'm a big fan of the loop style bands because of the infinitely adjustable fit. My style is mostly casual. The leather loop is squarely in my aesthetic. I only wear my Sport band during workouts/bike rides. I will sometimes wear it in the Summer. It's not my favorite, but I like how easy it is to clean after getting sweaty and/or dirty. The Sport Loop breathes better and feels lighter. Easy-ish to clean, but not as easy as the Sport Band. I prefer the look/style of the Sport Loop to the Sport Band or the woven nylon bands. I think I will actually buy another in a darker color like the Spruce Fog or Nike black.