I had an Islander 32 (the Bob Perry design). She was a good sailing boat. Really stiff, even in a lot of breeze, right up to the point the rudder couldn't steer her.
The best I ever did with her was 8.6 knots (GPS) in about 25 knots of wind, a little forward of abeam. The funny thing was that about that time I needed to fall off about ten degrees and found that I had no rudder control at all.
Some days, I still wish I had her instead of the Catalina 42 I replaced her with. It sure was a lot easier to take her out by myself or with non-sailing crew.