My local brick-and-mortar ARC retailer has one on demo with a phono. Paired with efficient speakers, they are big fans, and big fans of ARC in general. I am told that i/50s are very popular.
The last 3 times I visited, with no other customers in the space, they were playing it for their own enjoyment. They have lots of other options, and they choose to listen to the i/50.
I listened casually and it was very pleasant. I too am a big ARC fan, but I'm not in the market for an integrated, so I didn't listen critically.
If I were in the market for an integrated, an i/50 would be at the top of my list.