Yeah formally and on the record they tell you that previous experience means nothing, but the Capt. at my CFRC told me otherwise......
I don't mean to say that it helps with ASC, because quite honestly the little time I had before I went to Trenton (maybe about 5 hours) only helped in familiarizing me with the instruments (which can really be done using MS Flight Sim for a fraction of the price). The feel of CAPSS is COMPLETELY different that a real plane.... COMPLETELY. To put it lightly, the sim is ALWAYS going to hell........there wasnt one time when I could sit back and relax and not be correcting........but still it wasn't as bad as some on these boards make it out to be....and other than the 4-5 hours of plane rides I had going to Trenton, I had no prior flight training...only interest.
But yes as for being picked up, the recruiters to match you with a MOC that best suits your skills/experience/education and all the rest that goes with the app. (based on the choices you put down of course). Elwood is right, one's file consists of MANY different areas of your life such as he listed....same for me I think they touched on GPA once.
Though I was told that to be more competitive the next time around (since I had no cadet experience/reserve experience) he suggested I get complete my PPL. Its not that it will help you get through subsequent training or ASC, but tjhat it shows that your genuinely interested in aviation, and not that it just looks like a "cool" job.
From my understanding of ROTP applications, they're out of 18 points total, 9 for military potential and 9 for academic potential. I believe academic potential accounts for your high school average + # of post secondary years under your belt. Not sure about the exact point reward system though. And military potential is made up of everything else in your app., CFAT, work experience, physical fitness, leadership ability, experiences related to the MOC you are applying to, volunteer work, umm some other stuff I'm forgetting, and military experience (ie. RESERVES/CADETS-->which I didn't have).
If I could make one suggestion to upcoming ROTP applicants, it would be to show you have an interest in the MOC you are applying to, as well as building some experience through cadets or reserves.
I'm not a recruiter, but this definately sums up my experience of the process......well in terms of being offered the position anyway.....