I bought a Thinkpad specifically because they're built to be easy to upgrade and repair. They're aimed at corporations, so the IT managers value that ability. I've upgraded the RAM and installed an extra hard drive. I'm probably going to fix or replace the CD drive in the future, since someone damaged it and it only opens with the paperclip method now.
100%. I own four thinkpads now. I have upgraded all of them with no issues whatsover. I crammed 16GB of ram and a SSD into my old X-230 and it outperforms my dad's brand new Dell. Although to be fair, I am using Manjaro and he is using Windows 10. I forgot how incredibly slow Windows can be.