"fully open hardware" is a loaded misleading term, Just look up the mess open hardware logo is in, and different people involved trying to salvage it. Dave Jones/eevblog has some 1 hour long rant videos about it, he even redesigned this logo with some additional stipulations.
The fact is you can get full(1) hardware documentation for X220 and know what every single resistor/transistor/capacitor is doing. This part is easy. Thanks to hardcore hackers we also have full source of embedded controller firmware, meaning we control every aspect of this laptop. Here is an example Lenovo X230 repair showing off power of existing documentation http://imgur.com/a/V5FjN
On the other hand we got this olimex abomination with 5 year old phone specs, load 3 tabs in Chrome and you are running out of 1GB ram.
(1) The only thing missing for building your very own X220 are pcb layout files.