I took Nivek's suggestions (loosening the toestrap and increasing the forward lean) and I adjusted the highback to the higher position and that all definitely helped a lot... but while I'm getting closer to a decent fit... I still like the secureness my Burton CO2 give me. The RS models looks mainly a little bit stiffer but I don't think it would "fit" any better. I'm going to keep riding them a bit more so see if there isn't some other adjustment I can do... but I'll probably get rid of them if I can't figure it out after another month of riding and adjusting.
Though I bought last years flows m11, I am in the same boat, no amount of adjustment has let me get a consistent fit each time and I feel they are always loose. I am gonna give em the rest of the season to see if I have achange of heart, but I'll likely be chucking these in the bin.