I'm using an iPad Air 2, and I've found it sluggish for the past year or so. Still usable, but I've switched to preferring to use my phone for quick searches and 50% of idle surfing/shopping.

My dad is happy with his iPad 4th generation, which is one iOS version behind. But he is more patient than I, and also it's his only internet-connected device, so he's not comparing it to a fast PC or fast smartphone.

Yeah sorry, I wasn't really objecting to the parent comment. My sister used an iPad from 2007 until earlier this year, when she upgraded to an iPad from 2016.