You want aggressive ballistics and rifled or reinforced barrel. The other perks are subjective to your playable. I run close and personal and performance bonus because I am a very aggressive player with Voidwalker and I like to reliably take out supers with shotgun melee. Also thunderstrike can one shot if you are using feedback perk and are melees after you shotgun someone for an easy double kill. You engage 2 people with a shotgun. You get the first shot off on the first person and OHK him as he panic melee (which happens a lot as we all know) You melee the second guardian because that is immensely faster than firing the matador. That melee has Feedback damage bonus of 167 + 25% from you damaging the first guardian with the shotgun. On top of sniper range. That is a 208 melee. This is all circumstance yes. But this circumstance happens often in shotgun rushing so imho I feel my matador is a God roll for my playstyle. It's all about playstyle