do you need to fly down hills pushing the big ring?
i dunno.. i use a 44 big ring and don't run out with a 12, i just coast when i run out of gearing, and we have some good hills around here, routinely hitting 30+. never seemed a problem to me, really- and i know i push from about 36 to 99 inches with that setup.
i'd certainly worry about having a good range for comfortable spinning and climbing over speedwork FIRST. i honestly almost never use 44 12- but i think i might sping around 100-120 for cadence before i consider it 'spinning out'- so maybe that explains the discrepancy.