I did a similar journey in 2009, and bought my ticket from Helmut Uttenthaler - the guy who wrote that blog!
My trip into North Korea got postponed until 2010, but the rest of the Trans-Siberian (including checking out a purported North Korean labour camp in Chegdomyn) continued as planned.
The route was basically:
Geneva-Beijing-Xian-Beijing-Dandong-Beijing-What do I do with my double-entry Chinese visa and a week-Hong Kong-fly to Taipei-fly to Beijing-Harbin-Vladivostok-Khabarovsk-Chegdomyn-Khabarovsk-Irkutsk (first CouchSurfing experience!)-Moscow-Ukraine-Slovakia-Austria-Switzerland-fly to UK for university.
I liked Taiwan so much I went back the next summer for 2 months at an iPhone app startup, and enjoyed that so much I went back again from 2014-2018 and made many good memories (microSD, USB, DRAM factory).
About the long train journey though: the scenery is beautiful, and being offline for a while is very refreshing "Sorry I didn't answer your email, I was in Siberia". Worth doing every decade or so; it's about time I have another holiday like that. Maybe further south along the ancient Silk Road route.