I have a T450s with an i7 and 12GB RAM. It’s never felt slow to me apart from when my RAM broke and I was stuck with 4GB for a while. I can afford a new laptop but I just don’t want one. I only use it for work so the low res screen is fine.
I had a libre-booted X220 through college, and absolutely loved it. BUT it eventually couldn't keep up with my desire to be able to use Blender, Code::Blocks, and other more demanding software. Still miss that laptop.
My nostalgic laptop is the X200/X201. I owned a couple of them and from the pile of parts put together my dream machine with AFFS panel and deleted palmrest i7 with maxed RAM and Thai keyboard. Running OpenBSD.
I owned it and it was my sidekick for years. Took it to four different countries. At some point, I don't know why but I sold that thing for like $75, 7 years ago.
I have another one now, same AFFS panel mod and all, but it was built by someone else so it's not the same.