yeah the elevons are good in the potato family, just keep in mind that they are totally a novelty fin in that they give you some added lift and a super unique ride, but they don't feel like a traditional fin. there is a little extra drag/stickiness to your turns that isn't there with a more traditionally foiled fin.
I tried the Elevons on my SP during my quest for the perfect fin set-up for this board, which ended up being the Controllers. The Elevons were fast down the line but were not very loose. More of a stiff, unforgiving ride. The SP already has plenty of lift. My advice is to save the $200 and buy a set of Controllers at half the price. And the Controllers are perfect on my BP also.