I've had mine for 6 months. I like it for automatic sleep tracking (using the sleep watch app). The battery on the series 2 is good enough that it only needs about 30-60 minutes of charging a day (depending on usage). I also use the silent alarm it has to wake up.

When I go for a bike ride, it's nice to track that and be able to check heart rate, distance, etc while riding without pulling out my phone.

The cellular isn't enough for me to upgrade, I don't run so there's never really a time I'd be without my phone.

I've ended up wearing it about 23 hours a day, 7 days a week.