@rddvet and what did you do with your sidewinder?
Never took it home. Instructor was nice enough to just charge me a rental fee. Based on that experience I will likely never take a ccr class unless it's a rental or loaner unit first. I was lucky that I loved my first unit from dive 1. I went into the sw class excited and ready to love it and was profoundly disappointed ( in the unit not the class. Like any good quality class I learned some things I didin't know). I'm interested in the Choptima, but won't base my choice to purchase on a try dive. I'd want to do the crossover on a loaner or rental then choose to buy a unit from there. I try-dived the sidewinder about 4 years ago or so before I had any knowledge about rebreathers. I thought it was great at that time and that's why I was confident I'd love it. Once I had some ccr experience under my belt it was a different story.