As promised some pics from my trip so far. The train was on old Russian one, probably from before I was born. It was comfortable and warm, almost oppressively so.

I booked all the beds out for the princely sum of 29USD
Just a standard provincial hotel, comfortable and somewhat gaudy in decor.

Erdenet itself was built by the Soviets- it has fantastic infrastructure for a provincial Mongolian town as a result. The architecture largely follows the town planning philosophy of Khrushchev and Brezhnev- there are a lot of blocky panel buildings and Soviet mosaics.