I used to spin occasionally. But the health club fee was $85 a month, and I just wasn't using it that often.
My take:
1. It depends on the instructor. Some make it enjoyable, fun, and challenging. Some, not so much.
2. My club was somewhat of an upscale club, but even so, some of the equipment wasn't maintained well. Almost all the pedals needed new bearings.
3. If you want to learn to spin at higher RPMs, you'll get plenty of practice. Spinning high RPMs while standing up is challenging, but I thought it was nonsense. It's tough on the knees, and I never do that when riding the real thing.
4. If I lived where I couldn't ride this time of year, I'd probably be spinning right now.
__________________
Proud parent of a happy inner child ...