Train movements between stations are simulated based on the expected speed between two points and not based on GPS tracks, sadly, so it's not very useful if you want to check whether your train is stuck (say, due to traffic or signal failures). Notice that the circles representing trains occasionally move at unnaturally high speeds -- this presumably happens when a train enters a station and its location is corrected. It would certainly be useful to be able to see the actual real-time location of a train and not just the approximate location (and I'd assume that at least some of the maps from other countries are indeed based on real-time GPS data!) -- this exists for buses in Oslo (only available in the public transport company's app, unfortunately) and it's nice to know for sure whether you'll have to run to catch your bus or not.
(Several years ago when looking into the possibility of creating a real-time train map, I read that certain train operators and/or the national government considers publishing the exact locations of trains to be a security risk, so unless opinions on this have changed I don't have high hopes that we're getting it soon.)
Edit: I just noticed that the marker style changes if I choose something other than "Equipment" from the map style dropdown, selecting "driving/stationary" certainly makes it a lot more readable.