Is there any benefit to a tubed phono stage?

Can't have too many tubes! :-)

Actually there are some fine SS and Tubed phono stages. I'd make my choice based on tone and versitility, that is the ability to adjust so you can use different types of cartridges with different gain and loading requirements.

I have a tube pre and tube phono, but you CAN have too many tubes if implemented wrong it can mush up everything.

pretty much you either like tubes or you don't