I usually use a new razor every other day, but then I get a bit stuck with some of them for a few days. I have my favourites that I use more than others. Right now those are my Merkur 34G and my Schick Injectors. Before that I was hooked on my Slim Adjustable.
I enjoy rotating my razors: DE, SE, and injectors. I get great shaves with all of them (32). If I didn't I would retire the razor.
I rotate a dozen or so straights and 5 DE razors. I can't remember the last time I had any irritation or a nick. I rotate Feathers Polsilvers or vintage Wilkinson's in all of the DEs and get the same great results with all of them. I don't keep track of number of shaves with each blade. I usually toss the blade after I think its been used 4 times. Could be 3 or 5, I should pay more attention but use the straights way more now and can't be bothered tacking number of shaves per blade in the DEs. I am starting to get as good shaves with the straights now and usually only use a DE if I'm in a hurry.
I haven't rotated razors since I started shaving with a Weber DLC BullDog 3 piece.. I usually use two razors in the morning however, First pass is with a 1935 Long Comb Gillette "NEW" OC mated to a griestshaving FAT brass handle, followed by the DLC for the remaining passes..
