I’m planning to eventually get a smart trainer for the full Zwift experience. However, I have a small home gym with a spin bike always set up ready to go. I saw a video about putting power meter pedals on a spin bike and using it with Zwift. It seems to me that this might be pretty useful ongoing for when I don’t have time to set up the smart trainer with the bike, but do want a Zwift workout.
So, apart from resistance not being controlled automatically, what does someone on a spin bike with smart pedals miss out on? (Obviously excluding the feeling of being on a real bike). Can they still take part in races?
I’m trying to figure out how much of the full Zwift experience you get with this setup and whether it’s worth the cost.
For me, the two things you mentioned are about all i miss out on. I had a Neo (and tried a Kickr as well). I loved them, but there is only room for one setup here, so the spin bike won 
(my wife can do her spin classes, and i can ride Zwift)
I do feel a difference between the ‘freeness’ of a spin bike, compared to the mechanical resistance of the drivetrain on my bike. But it’s not massive.
The resistance is the big thing. In races (i still race on Zwift with the spin bike and power meter pedals) you need an extra level of concentration and awareness to spot the hills, and when to ramp up the resistance, and by how much.
And the added bonus is that i take the pedals off, mount them to my road bike when i go outside, and now i have like-for-like power readings between indoor and outdoor!
Thanks for the reply. Good to know that some people are getting a worthwhile experience with power meter pedals.