Nothing is perfect.
But in a genre that is filled with mediocrity, including but not limited to match engines that are crud, seasons that go on for too long in real-time, stupid features that give people with real money an unfair advantage, or just plain bad game design... BuzzerBeater stands out from the crowd as a game I really enjoy and that fact is unlikely to change any time soon.
The amazing thing about this is that, the game that this game takes inspiration from, (s)HatTrick, is one of those mediocre managers I mentioned. But BB did a great job in cutting away all the bad things about HT (shorter seasons in real-time and more league games is the big one), then re-inventing the game into a basketball manager that is, at risk of sounding cliche, easy to learn, but hard to master and actually quite deep once you start studying the match engine in detail.
Speaking of Match Engine, it's nice to see an online manager game where the results are predictable for a change. There's still some room for upsets, but good teams always beat bad ones and that's nice because I've played too many games where bad teams can get lucky coughtrophymanagercough. That kind of stuff is simply annoying so I'm glad that's not in this game.
In conclusion... this game is the most popular basketball manager on the web right now (not counting fantasy NBA) and it's easy to see why. I don't know much about BasketSim and Charazay, but from what I read in their respective manuals, both have seasons that are way too long, both fail to properly separate the perimeter game and the post game in their match engine, and neither of them are structured in a way that makes the league season feel similar a real-life basketball league, something that BB does a good job of doing with the conference system, playoffs, draft and All-star game (though it could be argued at the ASG is a waste of time as it stands now).
Ok, I'll stop rambling now :P.