I've had a sit on an r6. You're right lol - r6 is a much sportier, more compact riding position.
I wouldn't hesitate to recommend a Cat to anyone. Served me well.
Main reason I'm getting rid of it - I ride two-up a lot. My legs are short and the Cat is quite tall and top-heavy, especially two up. The 600cc engine doesn't enjoy hauling two of you through town either. Get it on the open road and it'll lunge along, mind.
I'm sure the 1300 Midnight Star won't be as fast or agile, but I'm hoping it'll be easier for me to handle and it'll make me smile in different ways