Hey! I thought I would give you my feedback. As a bit of backstory, I typically use Apple’s Workout app on the Watch because I’m only a “casual” runner.
Since I’m starting the couch-to-10K program from the very beginning, there are a lot of intervals during the first few weeks (e.g., 8 intervals of 1 minute running + 1.5 min walking). I couldn’t find a way to easily change the workout type from running to walking (or the other way around) mid-run. However, if there was a way to make a predetermined workout and “launch” it when I’m ready to run, that would be incredibly helpful. I noticed there is a Workout section in the Phone app, but I haven’t seen a way to add/create a new workout (it just displays saved workouts from the watch, I think?).
Once I get into the longer running sessions of the program, I can see myself using the app to track my stats - I love the modularity and how granular many of the options are! Until then, though, I’ll have to stick with Apple’s Workout app for the next couple of weeks while I work my way up there.