I have been in Europe for about 4 weeks now - and I have 1 more week before I go back to the USA.

I have the Eurail pass - good for 7 trips in 30 days.  It works perfect for me.  

My issue is around the supplements charged for most of my routes.  I don’t mind paying these supplements but I cannot do it online.  I have to go to a specific train station in my specific city to talk to someone about paying for my supplement.  Sometimes the lines are over 1 hour long.

My biggest issue was - my train from Prague to Florence.  I had to change trains in Munich.  I was given 30 minutes to change trains, so I thought that was good.  The train from Prague to Munich was 45 minutes late arriving.  I have already paid my supplement from Munich to Florence, but I missed the connection because the train was late.  I then had to sit in a line for 1 ½ hours to get this fixed.  When it was finally fixed, my next train left in 4 minutes.  I made it, but just barely.

It would be nice to be able to pay for supplements on the Eurail website rather than in person.