There is very little information about the advantages of one fin type over another. One study showed that the preferred fin was the one that the subjects had the most previous experience with. Consequently, selection of fins, in contrast to other diving equipment like regs and BCs, tends to be a highly individual and experience-based decision. Also, people are affected (whether they know it or not) by marketing hype. "Paying more" doesn't always mean you're "getting something better," especially with dive equipment. In the end, comfort, fit and how it works for you will be the determining factors as to "what is best," and it's best to try these things out prior. Is that always possible? No, because LDS wants you to buy one thing, and if you don't like it you have to go back for something else. Also, it's improbable that LDS has enough financial wherewithall to maintain sets of equipment just for people "to try" (in all fairness). My overriding principle about dive equipment? Keep it Simple Stupid (KISS)...Split fins aren't going to "give you more air time," nor are they (that much) "worse in currents." There really is no way to tell what are the "fastest fins" because everyone is different..."spring straps" are only another excuse to spend money on some other useless thing (IMHO) - I have the same straps on my original issue Avanti Quattros (and see these fins more often than any other type of fin on dive instructors, if that means anything), and they are doing just fine, thank you very much...I see no reason why anyone would need to spend another $30-$40 on springs...or $50 more (or more) on split fins...