Split fins: why not DIR?

[DRE]

One more reason (and maybe not the best): sometimes the only way to make headway in a high flow cave where there is no possibility of pull-and-gliding is to kick off against the ceiling: the shorter and more rigid the fin is the easier it is to do.
I agree with Jon, why spend $200 on a pair of split fins when you can spend $60 on a pair of Jet Fins that'll do a better job?

The only benefit I see for splitfins is for people who have extremely weak leg muscles (but then again hitting the gym might be a better solution for that).