I feel the HR tracker is surprisingly reasonable (I say "surprisingly" because I didn't expect it to work well at all), though I've heard others who use it for running and cycling say that it is consistently low. The distance/laps tracker is not reliable at all for pool swimming. Besides not working for kicking, if you have any kind of underwater kick then it will significantly under-estimate the yardage. But if you just do freestyle back and forth it is probably fine. I feel like the calories tracking is a little low too.
I've always liked the AW as a general-purpose device and I'm glad they added a swim workout to it. But I'm not very obsessive when it comes to fitness tracking; if you want to depend on a watch for serious tracking, I'd go elsewhere. As the review said, it would probably work well for OW swimming (and it has built-in GPS).