Noob posting... watch out.
I started with a pair of scubapro twin jets. They work and seem like they are a very efficient fin if most of the time you are using a standard flutter kick. However, I am recently realizing that speed of anything is not beneficial in the diving I'm doing. In fact, speed (and more precisely, rushing) has been my bane. My mentors continually stress the fact that I need to take things easy and slow things down. So I guess for me, a more efficient or more powerful fin is not what I need. Apparently precision is far more important.
I have since switched to scubapro jetfins. They are a paddle style fin that offers better control under water. They are very effective for frog kicking, a stroke that is quite useful when you are close to sandy bottom and for helicopter turns, a stroke that allows you to turn on a dime. They say that back kicks are only doable with paddle fins. I've tried but am still a work in progress. Perhaps split fin owners can comment on their ability to do back kicks.
One might say that twin jets or other split fins will allow a diver to overcome surge and current more easily than a paddle style fin. However, all of my dives have recently (last 8) have been with divers with paddle fins exclusively in pretty surgy water. No one has had any issues.
Edit:
BTW, also consider that another way to get the most result from the energy you expend is to present a more streamlined profile. Having all kinds of dangly stuff and pockets or whatever else hanging from your body will increase drag. The more streamlined, the less effort required.