I started riding the Litewave Wing 161 finless to experiment in lightwinds and a 13.5 Obesession and sometimes a 15 m Obesssion. I felt having four fins on your heel edge really bogged down the speed. Even in light winds, there is some bit of chop going on in the water and every time the front fins caught that chop I was loosing some speed. Taking the fins off was awesome, I really learned how to tear upwind at a steeper angle using the board itself like a massive racing fin. All the while not on a lightwind kite. I had hoped some of same findings would occur with my smaller twin tip and a bigger kite but I found no lightwind miracle there like I had on the Wing. I've also used my surfboard finless a bunch in light winds and that works well also if you are used to using a skimboard.
I still rode my RRD Style 132 ? x 40 (single channel) without fins for a while. It really is awesome without fins especially when you want to do those nose presses in the water. I'm not sure what they are called. I eventually put on slider fins .75 inch. At first finless is a bit wild and very skatey but I like that feeling. Once you get used to it, edging is no issue. I even loosened my foot straps to allow for easier exit and entry of board offs and my legs are not feeling strained from having to edge a little different. My knees are kind bad and I used to get all bent out of shape when I would do a trick to toeside, then pop to revert back onto my heel edge. For some reason, that would kill my knee. Now I just slide on the water like its not big deal and the knees feel fine.
I agree that loading for big jumps is trickier but everything else is about the same. Big landings don't always work out, you have to keep in mind you'll probably have to land with some downwind speed and then go to your edge. One major difference I've noticed is upwind-ability. When I'm getting crowded all of a sudden and want to go upwind to an empty area, I can apply what I've learned on the finless wing. I keep the nose of the board high above the chop and twist more into the wind. I doubt this could be used effectively with standard sized fins but it sure works with small fins, perhaps having a stiff board can also be attributed.