Oh

For me it was the other way round. I used to put Bridgestones on most of my bikes and it was only after I got the RF9 that this happy relationship ended. I'm sure they've probably improved since the time I'm referring to (a long time ago) but the type I was using on the front (BT21s?) were so bad at wearing prematurely just off-centre on the right hand side, that I looked around for alternatives.
The switch I made was to Maxxix and - almost ironically, in the context of this thread - I liked them well enough that they took over as my preferred choice.
As regards sizes (regardless of make), a 190 on an RF is just a plain no. I've used the 180/55 on mine since I first heard they were a more common size than the 170, which meant they would always be available, often at competitive prices. I've no complaints of them but I think my first RF did have a 170 on it when I first got it: I do actually still have some recollection that the handling lost a bit of its sharpness when I went to the 180, but I adjusted to it and it's never bothered me enough to want to switch back.