I already do this. I think there was a fair bit of discussion on the other thread about 18-card packs. The arguments in favour of running fourteen over fifteen are that a) it mimics actual retail Limited, b) you're usually stuffed to the gills with playables in cube already, so make people make harder choices during the draft portion, and c) with the utility land pile, you're going to end up with over 45 picks total, anyways.
I switched to fourteen a few months ago, and haven't looked back.