The LG G Watch, Samsung Gear Live, and Motorola Moto 360—the Android Wear models—have intuitive color touchscreen interfaces and were judged easiest to interact with. The Martian Notifier, Cookoo 2, and MetaWatch M1, which have push-button navigation, were determined to be the most difficult to use. In particular, the Cookoo 2's buttons were very hard to press.
I've been pleased to see swim-tracking trickle down into more affordable devices over the past few years. Fitbit's Flex 2 remains its most affordable device with swim-tracking features, priced at $60. But the $150 Charge 3, with its big display and smattering of smartwatch capabilities, is for a different audience than those who would gravitate to the tiny, quasi-cylindrical Flex 2. Even if you don't swim often, water-resistance up to 50 meters means users don't have to worry about showering with the Charge 3 or dropping it in the pool by accident.