I forgot to add a little imo: PT has most annoying sfx of all classes - he/she laughs when doing rocket puch. Every 10 sec - hahaha, hahaha, hahaha. But for solo content possibility to switch to tank spec really helps if you decide to solo heroic star forges, veteran and master modes chapters etc etc.

PT - melee and short range (4-10 m), feels way more sturdier then merc. Merc - long range, very simple rotation, have cleanse. If you are interested in complex rotations then imo choose PT. But you can try one first, then second class. With legacy gear it's not a problem.

She still doesn't drop any loot except deco box. Or at least I could not find any noticible loot box near her. Class doesn't matter. And no, loot didn't go directly to my inventory: I had 9680 tech fragment before her and I still have same amount after.

With 306 Victor set + 228 augs + The Life Warden tactical, medpack and healing stations I had no issues prepatch with all classes and companion set to dps. And I consider myself quite regular player. For some classes I set Ross to healing in last fight. You just need to give orders to Ross so he won't bug and stop shooting mobs (I died couple of times due to that). Victor set + The Life Warden tactical really help with all solo content. I forgot when I used class sets.

I am not sure if it's a bug or intended but it felt unrewarding at least: while I was doing Spirit of Vengeance [story] first time on another character bosses 3 and 4 (Bask Sunn and Heta Kol) didn't drop any loot. Except box with some banner. If I remember correctly on my other characters before 6.2.1 I could get loot from all 4 bosses.