One thing I never understood about the two shifter edges is why you have to have never used the form you want to change. If I ever find the time to actually play a shifter, I would want to play around with the form first to see how it is and if I could make it fit my style. And if not, then spin/roll. Even if I liked it, to have an option to check out another form later on might be a nice way to breathe new life into an old character.