All you guys out there that use different razors in your rotation, do you put a blade in each razor that you use regularly, or do you use one blade and swap it out? I've been using 3 or 4 razors on a pretty regular basis all with Israeli Personnas (to establish a sort of baseline, as I'm still pretty new) and sometimes I play hell trying to remember how many shaves I've had with a certain blade. I've taken to writing it all down on a calendar, but I was thinking it might just be better to use one blade and move it from razor to razor. Any insight or advice would be appreciated.