SPINNER is a brand name for an ordinary gym spin bike with variable resistance, for those who many not know.

1. Any aerobic training is helpful. I believe SPINNER brand spin bikes don't come with SPD-side pedals like most do. They do come with toe clips and straps, which should be used and tightened. If your gym doesn't have them fitted, find out why and where they put them when they took them off.

2. Pretty girls and boys and some encouragement from the instructor in a group spin session. Outside of a group session, no added benefit over other options.

3. Disadvantages are that it's not your bike, not your saddle, not your exact fit as it would be on your bike. Plus, since it's a fixie with a heavy flywheel, as the OP says, you only have to push down on the pedals, which degrades one's pedal stroke over time. And it's always too hot in a gym setting.

4. I used to incorporate training on an indoor cycle, but I gave that up because training on my own bike on a trainer (actually resistance rollers) is both more convenient and more effective and more versatile.

5. I used to do spin class once a week. Now I usually use my rollers/trainer three times a week if it's raining or too cold to ride outside or if I need to do a workout which can only be done on rollers/trainer.

6. I've used a Computrainer equivalent in a spin class setting and while it was fun, it's expensive and involves driving there. I have cyclist friends who love it and can spend the money on it. Quite effective.

OTOH, a good set of resistance rollers or trainer will set you back about $300 and will last you for decades, so that's quite cost-effective if you'll use it.