Well, I'm 46, so you're probably not quite as old, lol...
There was a lot of very good things in metal '16. A lot of people think it's a flushed year. I see the old school thrashers as taking everyone else to the cleaners. Metallica did a great job, though it's subjective to taste. Megadeth rebounded hard even if regurgitating a lot. Anthrax, a noble effort, Testament dropped an instant classic. Yet Destruction blew them all away. The new Overkill is already the one to beat in 2017.
Black metal is fully stale. I'm not sure even Ihsahn reuniting Emperor could save that genre. Besides, Ihsahn's solo work is so bloody interesting why should he go back? Doom...REALLY passe now. Been bludgeoned to death. We're in this goofy spot where people want to dissect the differences between sludge and stoner and right now because Baroness is so hot, everyone wants to jump on. There's a lot of good bands in this niche, a lot just copying and hoping to enjoy the ride.
I think Kyng is a pretty phenomenal band since they, like Baroness, are looking outside their sludge foundations and growing. Ditto for Red Fang. I love The Sword and applaud what they've done, though it's not for everyone.
What's a little annoying is so much hair metal revival and Hanoi Rocks wannabe-ism. So many new bands emulating 80s hard roc (and NWOBHM, for that matter) that it's fun for a few minutes, irksome overall.
Tech metal and prog...I'm just about over them. BTBAM rules that whole niche. Nobody can touch them. Gojira is amazing, though. Opeth...what can I say? Gods of evolution. I was hopeful about the "post metal" (dreadful term) bands like Pelican, Isis, Red Sparowes, etc., but only Neurosis is holding steady, ditto for Rosetta, a truly good band.
I would say that we're not really going anywhere in metal right now since all facets and subdivisions of it has been tapped, pushed, explored and only the cream of the crop is keeping the scene from falling under. It's about to, that's for sure. Right now, metal does hang all over Billboard, but then a non-pop or rap hot seller today is hitting about 3,800 unit sales, which is the new model of success. Sad.