First of all, the 733 is discontinued, replaced by the 3-blade 734.
I was in the exact same situation, and bought the 735 when all three
models were on the shelf. I bought it for the better design, and the
better performance (i.e., 2 speeds vs one, etc...). But more than
anything I bought the top of the line so that later I would not be
kicking myself for having saved a petty amount of money instead of
getting the best machine in its class. Been there, done that, hated
every minute of it.