Every good thing you've ever heard about it is true.
The curve from 1st to 14th level is pretty good, and doesn't do as big a disservice to demihumans as the 1-36 spread does in the larger BECMI rules. The endgame is solid, as players have the ability to build castles and strongholds, sail the seas, and explore in a satisfying way; the wilderness encounter tables are better organized than the ones from OD&D, but aren't as cluttered or unintentionally hilarious as the ones from AD&D1. I'm actually going to start using them for my AD&D2 campaign, as 2e basically has none.
Plus, the art is cool. I particularly like the illustration in the character advancement tables with the human fighter talking to the two halflings. It simultaneously conveys the physical scale of the two species, the fighting capability of most halfling adventurers, the condescending attitude the taller races have towards halflings (in many settings, but not all), and the halflings' impatience with this attitude.
|"Gettin' real sick of your shit, Marlowe."|