Would you recommend me to stay on the iPadOS 14.7.1 that came with my device for stability and (maybe) better battery life or risk that for security update reasons? What is your experience with going from iPadOS 14 to iPadOS 15? I heard an opinion on YT that iPadOS 14.8 "was gem".
The original version is always flawless, that has always been the case. Regarding performance, stability, and battery life, the advice that will never fail is “stay on the oldest version of iOS you can, if it is the original, even better”.
Why do you want to update? I don’t see you give any good reason, frankly. There are two: app support, and features. The former is way overblown: install what you will use in the foreseeable future when your device is on the latest version, and you’re all set for a very long time, and overall it isn’t even a problem until many, many years have passed, barring specific apps.
And features, yeah, some are cool, but if you get used to having what you currently have, you don’t really need any new ones, imo. I’d stay forever on iPadOS 14. Perfect performance and battery life for as long as you use the device. Remember, you can’t go back.
I mean, the only way I’d update (I wouldn’t, but for the sake of an exercise) is if the situation were like this: “I use my iPad for one app, and that app no longer supports iPadOS 14. I don’t use literally anything else, and this iPad is a paperweight for me without the app”. If the situation isn’t that critical, I’d stay on the earliest possible version. Of course, the original version is the best, and you’re lucky to have it. I’d love Apple to allow me to go back to iOS 9 on my 9.7-inch iPad Pro. I stayed on it for three years flawlessly until they forced me to iOS 12 due to the A9’s activation bug on iOS 9. Battery life was obliterated and never recovered. I have an iPad Air 5 now, on its original version (iPadOS 15.6 for me), and I’m never updating.