I had the watch they launched with, which Apple pretends didn't exist as they named the next model the Series 1 and this model never got a name. The watch improved considerably in the next generations, so you can do the math back from your Series 2 to get a sense of how truly bad it was.

As a counterpoint, I had a Series 2 for years and it worked really well. It was slow, so third party apps were not really usable, but the core functionality of the watch was perfectly fine. That is, until an unfortunate incident broke its screen while in the sea.