Alright am i the only one wondering why mega slowbro isnt used as much? like it is seriously a huge counter to mega metagross and talonflame because it is easily one of if not the bulkiest mega that can do something offensive as well (sit down mega sableye).
I think a lot of people make the false assumption that Slowbro is a Mega Slowbro lite, when that's really not true. Due to higher base defense, Mega Slowbro can afford large amounts of Special Defense investment and still have a higher Defense stat. For some comparisons:
+6 0 Atk Mew Play Rough vs. 252 HP / 80+ Def Mega Slowbro: 134-158
(34 - 40.1%) -- guaranteed 3HKO
+6 0 SpA Mew Hyper Voice vs. 252 HP / 176 SpD Mega Slowbro: 254-299
(64.4 - 75.8%) -- guaranteed 2HKO
+6 0 Atk Mew Play Rough vs. 252 HP / 232+ Def Slowbro: 176-208
(44.6 - 52.7%) -- guaranteed 3HKO after Leftovers recovery
+6 0 SpA Mew Hyper Voice vs. 252 HP / 24 SpD Slowbro: 301-355
(76.3 - 90.1%) -- guaranteed 2HKO after Leftovers recovery
Calcs are totally unreal scenarios, specifically made to show noticable difference in damage dealt to Slowbro. And that's all without getting into all the sets that MegaBro can viably run. Double Dance is a hugely overlooked threat, especially to teams that don't carry Toxic (see, most HO teams). Tanks sets are also sneaky underrated and Slowbro has great coverage between Scald, Fire Blast, Psyshock, Grass Knot and Ice Beam and gives balanced teams a lot of trouble (it can run through Hippo/Gliscor/Ferro/Tran and others with the right 3 move coverage). There's also CM-2 attacks which is a pretty good wincon. Its absolutely brilliant for balanced due to the sheer volume of threats it can check and its versatility (never thought I'd say Slowbro and versatile in the same sentence).
So yes, people are sleeping on MegaBro and you are not the only one picking up on it.