I recently got a Thinkpad T430s as a Christmas gift for my Sister, and since she doesn't know how to use Linux at all but has been using Windows for a while I decided to install Windows 10 on it.
First off, holy crap the default trackpad experience is awful. Whenever I briefly use the trackpoint to do something (say, while I'm eating or multitasking with my other hand, since I prefer the trackpoint when I can only use one hand) it disables the touchpad for about 5 seconds. Doesn't happen when I put my hard drive with Arch Linux in it, touchpad works perfectly out of the box. This may seem like a tiny insignificant think but it really bothers me. To add onto this, whenever I wanted to type and use the touchpad at the same time (Like if I was playing a video game), the touchpad/trackpoint just don't work whenever I'm pressing a key on the keyboard. So I did a little bit of digging and found out that this is a "feature" called palm check. So I googled how to get rid of it, found out that I had to install some crappy drivers from Lenovo, reboot the laptop, find the setting in the clunky menu not updated since 2007, and disable it, phew!
So I naïvely thought that, you know, 4 gigabytes of DDR3 RAM would be fine for simple web browsing, it's a little behind the times, but it should still hold up fine, after all I've been using my T420 for well over a year with 4 gigs of RAM and I've never had issues with that! Welp... guess not... Windows 10 took up 80% OF MY RAM WHEN I HAD NO WINDOWS OPEN, I REPEAT, NO WINDOWS OPEN! thanks, built in Windows 10 antivirus and bloatware. The only way I could drop it down to something not awful was by running third party scripts to get rid of some of it and tinker in the settings. As of typing this, 83% of my 4 gigabytes of RAM are being taken up on my T420 on Arch Linux, but here's the difference: I have two Firefox windows open, one with one tab, the other with eleven. I have Discord open, and I have Kgpg open, which is a tad bit more than IDLING WITH NO WINDOWS AT ALL! Like, I assumed that Windows 10 would work smoothly out of the box, but guess not... It is so embarrasing that Windows 10 is still the most popular OS out there. 4 gigs of RAM held up fine on Arch Linux, but I doubt it will hold up as well on Windows 10.