This is the one with Apple Fitness+.
This is the one with the intercom feature for HomePods, but make sure to go through the on-boarding process in the Home app first, since it doesn’t seem to want to work otherwise.
This is a small bug-fix update but well worth it, considering how buggy 14.0 is. I’m currently on the 14.2 beta and even that one is far from perfect.
Don’t forget to backup your device first and please be warned — iOS 14 and iPadOS 14 are still chock full of small bugs. You might have some software issues with your apps too, if they haven’t been updated yet.