CRRCsim is well know in the slope soaring world for providing a very nice experience, and great sensations. Here and there are organised friendly club competition, a good opportunity to meet together during the winter season.
Joel Lienard posted on his website the study of Luca Gasparini, on of the major contributor of the CRRCsim software. In this study, Luca analysed the perfomances of the various F3F gliders available in the main distribution or in the add-on, and discovered that they have, for most them, serious flaws which produce unrealistic simulations.
You can read this interestting study here.