If you want to replace your 235 with the Apple Watch I would wait until iSmoothRun announces full compatibility with the new model. It's the only running app that really has similar functionality to a Garmin watch. Even still, there are a couple of things to be aware of with running with the AW - first the screen is not always on, so there is a bit of a delay when you look to see your stats. I presume this is faster with the new watch, and I learned to live with it on the original watch by delaying looking at the watch by 1/2 a second after I raised my wrist. Second, the lack of an array of hardware buttons can be difficult to live with depending on how much you personally need to interact with the watch during your run. Interval timing, for example, can be difficult.