As I read all the posts on this site, I seem to be the only one to own a R9. I have serial number 153 so I would assume some else has one somewhere.
With my eye sight and glasses, I have to choose to focus on sights or target. One will be out of focus. I do faily well at 7 yards and can cover my hits with my hand.(usually) I have sights on every other gun I own and in a stress, fast moving situation at night, I don't think they would be that important. Only at the range........
These are my thoughts and yours may vary.