I was wondering if the split vortex fins really work much better than the regular ones or if they’re not worth the money.

The difference comes with your kicking style. If you want an easier kick with more control I would suggest the split fin. If you would rather have more forward thrust with a little more difficult kick then a longer solid fin is for you. I personally don’t like the split fin. To me it feels like I’m going to kick my knee off because I don’t feel the resistance when I kick. My girlfriend on the other hand loves them and won’t touch my force fins at all. Check with your local dive shop or your buddy and try each out before you decide what type to buy. There are also many hybrid fins that have some of the qualities of both. Good Luck in your search.