It does require just as much attention behind a towplane as a winch when close to the ground as a cartwheel is very bad news.
Once you have 50' I find it easier in my 27 (70% CG) with a CG hook than the K-21, even when the towpilot takes a thermal. A forward hook produces a yaw couple in turns that requires compensation with rudder.
The 20 with 80% CG is considerably more frisky
