Parked him in Sanctuary- haven't seen him since.
The idea of him finding loot was great, but what happens is you get a message that he found something. He grabs it, runs (sometimes) towards you and drops it in the tall grass...
Hope you weren't busy and had a clear line of sight on him when that happened. Most of the time, I never recovered whatever he found.
Other companions are pulling npc's and blocking my path, but at least they're not hiding loot and barking while I'm sneaking.