I love it too. I had it last year and thought it was awful - you couldn't watch replay games when you wanted but had to catch the broadcast, and its start hour was not indicated anywhere so you could click on a game and just watch the final minutes while wanting to watch the whole game... -. Plus there was a lot of problems during live games.
I wasn't planning on suscribing again this year but I had a chance to try it for free and loved it. Now it's in HD (really beautiful), you can watch replay whenever you want the day after the game, and all games are available, while it was not the case last year.
There are blackouts on certain games here, the ones that are broadcasted on French TV, but when you watch live you can find the channel corresponding the game and go through the blackout so it's great.
To resume, I think that, at a fair price, League Pass is perfect for international fans, because, if you have good enough internet connection and a powerful computer, you can watch NBA games : and that's huge here where the national TV basically broadcasts a game by week if you're lucky.
And it allows you to watch all the Celtics games so it's perfect! Kudos to the NBA for creating a great and reliable system this season.
I'm wondering how useful it is for Americans, however? If I'm correct, you can only watch games that are broadcasted on ESPN and ABC, and on the local Comcast Sportsnet Channel? So basically, it allows you to watch games from other teams which are not big "showdowns"?