I personally have used it in loadouts before, but I see myself reducing it to level 1 or taking it off entirely since it feels as though it doesn't help as much. I mean overall you barely see an increase in parts by the end of the game, probably as much as 1k, but to justify the fact that it is literally taking half of your loadout...meh.
I would say if you have a stockpile of them, just use the increased parts one-use booster for basically a free collector 1 that costs nothing along with skills that get you parts such as crafter and first aid.
Depends on your style, if you like hanging close to your team, I'd definitely go with First Aid, Reviver or Crafter. I'm usually ahead of my team or flanking so I use Collector 2 to get my long arm upgrades and armor faster. I would probably use Crafter instead except if your team is winning there's maybe 1-2 items in those supply caches, so I just use Collector 2 for more all around booster. Also like Crafter, First Aid and Reviver won't get you many parts if your team is running over the enemy because no one is getting hurt or dying.
It is a bit selfish, but if you're using a purchasable weapon, it can help pay for a lot of ammo.
I tested it out for half a day and barely saw any noticeable difference. It didn't help me get a better score in terms of parts. It didn't make a noticeable different in getting enough parts for puchasable weapons.
You are better of using First Aid 2-3, reviver 2-3 to get parts.