This comment has nothing to do with the latest Nimbus 4DM accident:

However, in regards to some comments about a glider spin developing into a spiral. If you have not had that happen it can be a real surprise. I was spin training in a 2-32 that would do 1/2 turn in a spin and then go in spiral. The sight picture was the same, only different was rudder opposite the rotation did not work. I spotted the problem after about ¾ of a rotation but was very surprised that the spiral did not look any different than the spin I had always assumed I could tell the difference. Now picture this is a slippery modern glider of any wing length, nose 70 degrees down or more. Would very quickly go through VNE.

The most fun flying I have done is in a Nimbus 4D or ASH-25 as a shared experience is the essence of human nature. Two pilots can make one very good flight!