Now that my life wound down a bit, time to post :D
my thoughts are similar on Braviary as it has multiple things that set it alongside other birds and away. On bird spam teams it would have to fight against STaraptor mainly as they carry ridiculously similar coverage (Fighting move, Normal typing attacks, Strong Brave Bird) and Staraptor would as it wouldn't need to rely on priority as often, stupid power in Reckless, and its fighting move allows it to keep attacking instead of making it weaker with each use. In a way, Braviary would need to look elsewhere to find its goals, and balanced seems best as its not too fast, fairly bulky, and has nice coverage to abuse with its defiant antics. The one I think I would like would be this:
Braviary
Sheer Force
Life Orb
Brave Nature
252 Atk / 100 Sp Atk / 156 Spd
-Brave Bird
-Extremespeed
-Heat Wave
-Super Power
This, while not defiant, gives it great utility over the other birds as with this set, it can 3HKO Aegislash while not making contact and still hitting with stupid strong damage. He sacrifices the ability to be a defiant check, but basically makes him a little scarier as he really couldn't be accounted for. While this set already really exists for normal Braviary, the threat of a STAB 80 priority move can not be under estimated. I would like to see it in practice, but it may not be its best bet.
The whole point of making braviary viable was to add another good defiant user. Sheer force affects one move, replace heat wave with shadow claw, you dont get an attack drop with kings shield, you can invest your ev'smmore in spe or hp, form a cooler bird core and gives you something to switch into defog.
calcs
2 4 Atk Mandibuzz Foul Play vs. 252 HP / 0 Def Braviary: 415-490 (102.7 - 121.2%) -- guaranteed OHKO
+2 252+ Atk Braviary Brave Bird vs. 252 HP / 252+ Def Mandibuzz: 288-340 (67.9 - 80.1%) -- guaranteed 2HKO after Leftovers recovery
0 SpA Zapdos Thunderbolt vs. 252 HP / 4 SpD Braviary: 296-350 (73.2 - 86.6%) -- guaranteed 2HKO after Leftovers recovery
+2 252+ Atk Braviary Extreme Speed vs. 252 HP / 252+ Def Zapdos: 220-261 (57.2 - 67.9%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Life Orb Latios Draco Meteor vs. 252 HP / 4 SpD Braviary: 348-411 (86.1 - 101.7%) -- 12.5% chance to OHKO
+2 252+ Atk Braviary Extreme Speed vs. 4 HP / 0 Def Latios: 331-391 (109.6 - 129.4%) -- guaranteed OHKO (that is nice)
+2 252+ Atk Braviary Brave Bird vs. 252 HP / 0 Def Mega Scizor: 309-364 (89.8 - 105.8%) -- 37.5% chance to OHKO (you win then)
+2 252+ Atk Braviary Superpower vs. 252 HP / 232+ Def Skarmory: 158-187 (47.3 - 55.9%) -- 25.8% chance to 2HKO after Leftovers recovery (pls)
+2 252+ Atk Braviary Brave Bird vs. 252 HP / 252+ Def Mandibuzz: 288-340 (67.9 - 80.1%) -- guaranteed 2HKO after Leftovers recovery
0 SpA Zapdos Thunderbolt vs. 252 HP / 4 SpD Braviary: 296-350 (73.2 - 86.6%) -- guaranteed 2HKO after Leftovers recovery
+2 252+ Atk Braviary Extreme Speed vs. 252 HP / 252+ Def Zapdos: 220-261 (57.2 - 67.9%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Life Orb Latios Draco Meteor vs. 252 HP / 4 SpD Braviary: 348-411 (86.1 - 101.7%) -- 12.5% chance to OHKO
+2 252+ Atk Braviary Extreme Speed vs. 4 HP / 0 Def Latios: 331-391 (109.6 - 129.4%) -- guaranteed OHKO (that is nice)
+2 252+ Atk Braviary Brave Bird vs. 252 HP / 0 Def Mega Scizor: 309-364 (89.8 - 105.8%) -- 37.5% chance to OHKO (you win then)
+2 252+ Atk Braviary Superpower vs. 252 HP / 232+ Def Skarmory: 158-187 (47.3 - 55.9%) -- 25.8% chance to 2HKO after Leftovers recovery (pls)
Espeed braviary isnt that great, only winning if assuming the opponent doesnt predict the obvious switch. Fur coat aroma is much more meta changing as it gives us a physically defensive fairy (togekiss is meh)