I'm not a big fan of round barns, I like the U shaped ones better. I don't like arenas with a arena directly attached because of the dust, so an arena with a roundpen attached does not sound the most appealing. If you took out the roundpen in the middle and made the barn smaller (bringing the stalls in), there would just be a circle in the middle. I guess you could put in tie rails or a tack room in the middle, but I feel like round barns are more expensive and not as space efficient.
“Good things come to those who wait… greater things come to those who get off their ass and do anything to make it happen.” - Unknown