I don't understand why people think that Noivern lacks power. Timid Specs Hurricane and Draco Meteor tear huge chunks out of everything. Frisk + U-turn provides excellent scouting, and Noivern even has good support options, such as Roost, Taunt, Switcheroo, ect.
IMO, Noivern is a better user of Specs Draco Meteor than Latios.
Lets not get ahead of ourselves, here. Latios is much better than Noivern as a Specs user. Not being weak to Stealth Rock is a huge selling point, since Draco Meteor does force you to switch after you use it. Also, take a look at its other options. Hurricane is horribly inconsistent (Focus Miss was called that for a reason), and though Noivern gets coverage options, they aren't very good when you get locked into them. Latios packs more raw power than Noivern, making switching into it less of a question of guessing the move and more of a "Who gets blasted by Draco Meteor this time?"
252 SpA Choice Specs Noivern Draco Meteor vs. 0 HP / 0 SpD (100/100/100 mon): 261-307 (76.5 - 90%) -- guaranteed 2HKO
252 SpA Choice Specs Latios Draco Meteor vs. 0 HP / 0 SpD (100/100/100 mon): 318-375 (93.2 - 109.9%) -- 56.3% chance to OHKO
Granted, Noivern is a lot better at LO sets than Latios, since it actually gets coverage and can use those options appropriately when it switches attacks.
Regardless, 97 Sp Attack will never be considered powerful in OU. Take a look at some of the attackers in OU right now and compare.
252 SpA Noivern Draco Meteor vs. 0 HP / 0 SpD (100/100/100 mon): 174-205 (51 - 60.1%) -- guaranteed 2HKO
252+ SpA Aegislash-Blade Shadow Ball vs. 0 HP / 0 SpD (100/100/100 mon): 160-189 (46.9 - 55.4%) -- 69.5% chance to 2HKO
252 Atk Terrakion Close Combat vs. 0 HP / 0+ Def (100/100/100 mon): 178-210 (52.1 - 61.5%) -- guaranteed 2HKO
252+ Atk Choice Band Talonflame Brave Bird vs. 0 HP / 0+ Def (100/100/100 mon): 214-253 (62.7 - 74.1%) -- guaranteed 2HKO
Noivern has to use Draco Meteor to keep up with other unboosted attackers, which is pretty bad when you consider that Draco has that side effect going on. After a Draco, Noivern is pretty much fodder for anything not weak to its attacks.
I don't mean to say that Noivern is bad, because it isn't, but if you're looking for 2HKOs on nearly everything Noivern is not your mon.