As an owner of two Lenovos, I voted "no." I read on Lenovo's site one time about a budget desktop having some kind of aluminum foil liner inside after malfunctioning after a couple of months, a turn-off. The Intel ME vulnerability affects my workstation and it seems it affects a number of these Yoga 520 models also so you'd have to patch it and then keep it in the back of your mind. So, yeah, I'd invest in something else.
The very first boot can take quite some time, it's only once. I don't know about the pen, never used one but the finger print reader is a very nice option and you should hold out for it. I suppose it's stupid to ask a high security guy why he won't shop on line but why won't you shop on line? You of all people must have an incredibly secure setup?
If @Umbra, is anything like me then i prefer a bricks and mortar store, i like to see the quality (or lack of it) in real life, i want to touch it, feel it, try it and if needed, ask questions and then i make a decision. For me it's not about not shopping online because i do for certain things but for the most part i prefer a real shop. If he had bought this online then he would have been seriously disappointed
In August I bought a Lenovo 520 Yoga for my wife (she had an old Lenovo Thnkpad dual core Celeron P4600) with the Pentium 4415U Processor (2.30GHz 1866MHz 4MB Ram) and 128 GB SSD. It was fairly easy to put in the Hybrid 1TB drive of her old Lenovo. Chrome launches in just a second (we have 200 MB internet, so we still get 100-120 on wireless). The screen is sharp and full HD. Batterly life is less as promised, but still way better than old laptops.
I like Lenovo: (but Dutch always like cheap stuff ), I only have positive experiences with Lenovo laptops.