Not to belabor the "Splits vs Anything Else" argument but, physically, none of the mechanics described in this article holds up. There are certainly vortexes created with solid fins and, in fact, they may extend downward to a greater degree than split fins. Stirring up silt is a matter of care not fins.
I have had both types and settled on splits because of a (perhaps perceived) ease of flutter kicking. I can do a frog kick, helicopter and backup using splits. You also can use the split design to flutter slowly at a relaxed speed. The bottom line is that the only thing that matters is your own opinion of the value of the type of fins. Your buddy's opinion only matters to help correct your technique. No style of fin is going to help that.
I have had both types and settled on splits because of a (perhaps perceived) ease of flutter kicking. I can do a frog kick, helicopter and backup using splits. You also can use the split design to flutter slowly at a relaxed speed. The bottom line is that the only thing that matters is your own opinion of the value of the type of fins. Your buddy's opinion only matters to help correct your technique. No style of fin is going to help that.