The 190/55 gives a 22% larger contact patch at standard pressure offering more grip at lean and as the sidewall is slightly taller it flexes a little more at lean keeping more tyre in contact with the road and pushes the sidewall out under the weight of bike and rider moving the edge of the tyre away from the road thus making it harder to get to the edge of the tyre. I tested various sizes on a recent trip to the track and the 190/55 was by far the best tyre size. On track at standard pressure once hot the 190/50 loses edge grip under hard acceleration the 190/55 doesn't. The 200 wide was too wide a tyre and you couldn't use all of the tread before running out of front tyre edge grip. IMHO Pointless to fit if you can't make full use of the part of the tyre that offers the most grip.
IMO the best tyre for our bike for me personally is the 190/55. If you run standard pressures and ride reasonably quickly you'll find you can use all of the available tread when cornering, especially once the tyre is up to temperature.
4 wheels move the body, but 2 wheels move the soul.
1982 Honda CB750 BOL D'OR
2017 Kawasaki GTR 1400
2017 Suzuki GSX S1000