So I did a super scientific test this weekend and skated the R1/O1 back-to-back then decided to try both at the same time. I was using the H5 insert on the R1 and keep the O1's center bolt pretty loose. I definitely feel (and see) a lot more rocker with the O1 which forces my muscles to work more when stationary, but when I was skating with one chassis on each foot, the difference didn't feel as drastic. I could do C-cuts on inside and outside edges about the same and didn't feel much of a difference with transitions or the turning radius. Granted, this was skating in a parking lot and not a game situation, but from my initial skate on the R1's I thought there would have been a more noticeable difference. The MPC Freestyle wheels provided me MUCH more grip than they did on the smooth concrete surface I skated on last week so I am definitely going to keep these wheels on for the time being. Biggest difference had nothing to do with the chassis itself, but rather the boot I mounted the R1's to since they're brand new and I'm still breaking them in.
Looking forward to others who have both chassis giving their impressions