I’ve been using a cellular Apple Watch for about a year now. I like how the eSIM part is handled through the carrier in the Watch app, and after setting it up once, I didn't have to think about it all. I even started leaving the house without the phone - just watch and headphones. And for runs and quick grocery shopping, it's perfect - Apple Pay, calls, messages, and music are all right there on my wrist. I think adding the eSIMto the watch is one of the best things Apple ever done.
RE: Apple Watch 3 LTE full review: This will change your lifestyle, but not everyone needs it