I’ve own the Xoss for a few months now, and for my purpose I find it very capable. Before removing my old cabled bike computer the speed matched perfectly the Xoss took a second or two to register you are accelerating (it's to be expected). Battery life is good, user friendly adding HR monitor other sensors.
Synching to Strava I had one instance where I struggled to find my recent event in the Xoss app, I had to shut down my phone for the updates to complete not had any issues since.
I’ve said that just say I’m happy with my purchase.