Personally, given all the potential for unrest across the EU this summer, I would avoid going there if I could. Especially with children in tow. There are far safer and equally pleasant places for destination travel this summer.
Also, the reason I recommended trains is one actually gets to see some of the country(side) one passes through on the way to a destination, rather than overflying it. More bang for your travel $$ without a massive penalty in time, and one of the biggest benefits of going to the EU.
Just my opinion.