It has some blackouts, including games that are on national TV (ESPN, TNT, and I think NBATV, which is kind of stupid for the NBA to black out. Some of these games stream on their own sites.) It also blacks out "local" broadcasts; when I lived in Seattle, I couldn't get Portland games.
It has a 2-tier price system. At the lower price, you select up to 7 teams to watch; to get all 30 teams, you have to pay a little bit more.
It's not a perfect system, but it's getting better.
Like MLB's option, League Pass blacks out your local games if they're on TV. One hopes that next time around the TV contracts include a mechanism for a) revenue sharing with the networks for these packages, and b) showing online streamers the same ads they'd see on their local affiliate.