My success rate with upgrades at the 72 hour window has been about 80-90%, however, sometimes you have to call two or three times in order to get a helpful agent. I find that many times the person answering sounds as though they are new to the job. I have found that the YVR-YEG and YVR-YYC flights are getting more difficult to get advance upgrades on due to the frequent F28 flights being removed from the schedule. How about your success rate?