I find the new version of the site more practical, as you can enter stations: https://www.chronotrains.com

I always thought of this visualization type as kind of a gimmick, but recently used this site for planning a vacation. I was visiting one place in the middle of the country and wanted to find some time efficient way to travel to "some coast" as the second part of that journey, inside the UK. The travel time was very much dependent on the specific main lines rather than geographical distance, so that was very helpful.