Normally I windsurf on a Jag 125 and windfoiling on a Stingray 125. Last year I was really overpowerd on the Stingray and that was a perfect moment to put a fin under the Stingray 125 and give it a try.
It planes relatively early, but after that it doesn't accelerate. Once planing the windward corner tail will be pressed into the water and this works as a break and it feels like a balance act between stalling and accelerating. To counter this feeling the board needs to be sailed extremely flat. The position of the back foot must be really inside in the middle of the board, so it is not possible to press against the side of the board. After a few racks I decided to switch to the Jag and the difference was night and day!
With so many drawbacks my conclusion is that it cannot be used as a substitute board for windsurfing.