I have elected to uninstall FitOS Beta because it's too buggy and often times leaves my EX-5s unusable.
Launching Connect from the FitOS home screen was a huge issue as most times it wouldn't find my bike. I would pedal, toggle back and forth between the home screen and the app, power cycle, and unplug from power... sometimes with success after a few tries, sometimes it would take 30 min or more of this process.
I purchased the bike to augment my real-bike riding. In the event I can't get out (rain, snow, schedule, whatever) I want a bike that I can jump on for an hour whenever the time's convenient for me. There's no convenience in messing around with a bike for 30 min or more just to get it to function as advertised and expected.
I understand this is the Beta version and the disclaimer was very clear on the probability of issues. However, it feels a bit too under-baked even for Beta release.
In addition to the app-to-bike connection issues, which is the deal-breaker for me, I would suggest addressing the following:
Make the app and the hardware (the heart rate function in particular) 100% compatible with Apple Watch and iPhone. I think this should be a one-and-done connection when setting up the bike initially rather than every time I ride, and definitely needs support in Worlds and Freestyle.
Work out the bugs with the bluetooth resistance controller connection. One out of five rides has me spinning the resistance knob as the bluetooth controller can't be found.
Often times I choose scenic rides as I'd rather set my own pace and listen to my own music via my iPhone > Spotify > JBL bluetooth speaker. Using Spotify and the Fit App simultaneously along with Echelon on my Apple Watch as heart rate monitor results in huge audio feedback on the bluetooth speaker. The problem doesn't present when using bluetooth earbuds in the same scenario.
Lastly, in an effort to let the participants on this forum know they're being heard, some response from the developer would be nice.
I understand these are all first-world problems... probaly meaningless to some, more important to me. But, this forum is for feedback, right?
I appreciate the vision for FitOS. I think it's going to be a fantastic experience if the resources can be allocated to develop it properly. Thanks for all of your efforts!