I bought a Lenovo T431s around 5 years ago. It's quite slim and not very heavy and still going very strong. Since I bought it I have upgraded the following: *

I bought a Lenovo T431s around 5 years ago. It's quite slim and not very heavy and still going very strong. Since I bought it I have upgraded the following: * New SSD * Added extra RAM * Upgraded the screen to full HD IPS (turns out the screen of the following year's model is an exact fit for this one) * Bought a new power brick (funnily, this is the only thing that failed on me in the 5 years) All components were incredibly easy to install, even a layperson could do it with no issues. I can't see myself buying a new laptop for the foreseeable future unless this one somehow bites the dust.