The other issue with an older eeePC is the original SSD may have non-trivial wear issues and the battery is likely shot. Unless you get the machine for next to nothing fixing those issues will cost as much as just a brand new cheapo laptop.
I really miss my old eeepc901 some days but I agree. Going back to those slow atom processors is really a nonstarter. But the size and form factor (with exception of the nonstandard screen aspect ratio) was just about the perfect 'take anywhere' laptop. I used Ubuntu on it and if I had to do it again in this day and age I'd try to see if I could make Ubuntu-Mate to work on it. Being able to set the font sizes and the icon sizes made that nonstandard screen aspect ratio work far better than it ever did in Windows XP.