Good for you on spin class. I love spinning. I'm certified to teach actually, but not in practice at the moment. I was a spinner first, then re-found my love from childhood of riding a bike outside.

Spinning can let you focus on different aspects of your riding while not worrying about cars running you over. I love being able to just close my eyes on a nice quick seated flat in spin class and do nothing but focus on making lovely circles towards a perfect pedal stroke.

AND... I even have time to take a mental vacation to somewhere nice I would love to ride outside.

Yeah for spinning.