The feature's good... except that with how the spells work, all it does is make necromancy slightly less shit.
I mean, I understand why they did it, but massing hordes was only ever circumstantial back in 3.xe. Most of what you'd do is find a nice big nasty thing to reanimate, and use skeletons to crew ships, guard places, serve as cannonfodder, &c. Even if they let you do something like control as many Medium/Small zombies or skeletons as you could fit into the 60' radius circle times the number of Animate Dead casts you get, it'd still be pretty lame.
Either you're wasting all of your spells on undead upkeep, or you're using all of your spells on undead upkeep to deal with problems that could just as easily be solved with... spells! The only real use I see for it is as a supplementary spell for non-necromancer wizards to make disposable trap-checkers. The Control feature is sort of nice, until you realize that most of the things worth controlling have a decent shot at beating the DC, and such situations can be readily resolved with application of fire and swords anyways. Unless you really wanted to infect yourself with vampirism or something, I suppose.
Part of this could just be my innate dislike for the combat elements of necromancy, especially in 5e -- no thought involved, just send in the zombies and skeletons until the targets are dead or you have to run away, doing nothing but blasting with cantrips in the meantime. I also had a thorough distaste for Leadership shenanigans for similar reasons, so maybe it's just me being silly.