I had an lg g watch r for a while, and now have an Apple Watch (first gen, SS)
Haptics: Apple Watch has nice, quiet haptics - android wear by contrast was more like a usual vibration and that could be quite noisy in quiet situations. On Apple Watch in silent mode is great at providing discreet notifications. On the other hand, it is really disapppointing that Apple Watch doesn't allow more customisation of the haptics. You can tap out a custom vibration pattern for notifications on iPhone, yet you can't carry that over to the watch. It would be such an obvious improvement being able to tell who is sending you a message or calling you. Especially frustrating because android wear lets you do that, and it's great.
Telling the time: quite a useful thing for a Watch to be able to do. But here Apple Watch falls down by not having the option of an always-on mode. Android wear always-on is a godsend. I often glance at my watch without making large wrist movements and Apple Watch is annoying when I can't check the time by doing this. I don't need onboard GPS so let me choose to use the battery life for something I'd find really useful.
Watch faces: hands down (sorry) android wear wins here. There are a couple of usable Apple Watch faces, but I hate being restricted to just a handful of presets, along with limited customisation of complications. Using an app like Facer on Android wear you can easily create a completely custom Watch face and custom complications in any locations you want.
Complications : complications on Apple Watch are much better now than they used to be, with third party support. But they are still quite limited by not being directly interactable - they all display some info and jump to an app (except the stopwatch complication on the chronograph face). With custom faces on android wear you can easily have buttons that do things right there, rather than jumping off to an app - e.g. Stopwatch, timer, toggle weather display. With a little work you could set up a face that did most things you wanted to do without ever having to leave the Watch face.
Key things I really hope Apple Watch adds soon to make it that much more usable for me would be
- custom haptics
- always on mode.
- custom watch faces (third party or make your own), including complication locations
- interactable complications