Are you not using the W520 anymore? Your posts were very useful in configuring mine.

I wally like W520 - but it has one drawback for me - it needs at least 135W PSU - which means I can not use USB-C adapters ... but the thing I need the most from W520 (comparing to T520) is that quad core CPU ... and I just bought T520 with quad core CPU - unfortunatelly also with Nvidia 4200 card ... but I will seek for one with 'only Intel GPU'.

The two W520 I have - I will clean them up and sell some time.

So for TL;DR - I will replace mine W520 with T520 to have it as a backup :)

Regards.