I signed up. I was using DirecTV Stream solely for Brewers' games so the switch to Bally was obvious. My free trial for DTV was coming up so the timing was perfect and was happy to spend far less per month for the only thing I needed DTV for.
As far as the quality, for streaming, I found the quality to be on par with anything else live on Hulu, etc. I had the game on my computer but then downloaded the app through my Fire Stick and had the game on the TV, too. So I can't be certain about multiply monitors or TVs but I assume it won't be an issue.