Here are my opinions between the two... take it for what you want =)
I ran a 180/55ZR17 Pirelli Dragon Supercorsa Pro for 1400 miles (on a 5.5" stock wheel) bike felt great but didn't know any different as this was the first setup. Was a little heavy in my opinion to turn in.
I ran a 180/55ZR17 Pirelli Dragon Supercorsa Pro for 3000 miles (on a 6.0" BST wheel) bike had a different almost progressive feel on turn in because of the 180 being stretched over a 6.0" wheel it did flatten out the profile of the tire a bit, but I had plenty of traction, good lean angle, and good tire wear.
I ran a 190/55ZR17 Pirelli Dragon Supercorsa Pro for 1200 miles (on a 6.0" OZ wheel) bike turns in awesome, the 190/55 adds a substantial amount of rear ride height to the bike making it turn in better than ever, got rid of the progressive turn in feel. The only issue I have is there is a ton more weight put on the front end now and it isn't a big deal solo, but when doing two up rides the front end gets a uncertain feel on it, keeping me from gaining any confidence in it, other than that I could adjust the front geometry to compensate but I love the way it turns in currently and wouldn't change the set up for the world.
I have not ran a 5.5" wheel with a 190/55ZR17 on my 848 but have extensive track time on an R6 with the 190/55 setup and the tire worked better than the 180/55 as there was a ton more contact patch, but to get all the way over on the tire your elbow was in the pavement and the tire did produce odd wear patterns, it was definately squishing the tire at that time. And would prefer to run a 6.0 rear.