Travel for Genealogy Research

I'm going to Paris in May with my best friend, whom I've known since kindergarten.  I mention this because yesterday I wrote the check to the tour company.  We will be spending a week in Paris, visiting all the wonderful places I've dreamed of seeing:  the Eiffel Tower, the Louvre, Versailles to name a few.
As I was planning this trip with my friend, it made me think about all the  places I would love to visit for genealogy research purposes.  My son's great grandparents lived in Trier, Germany, their whole lives, running a small hotel there.  His family also has a line that can be traced to Scotland.  My husband's grandfather immigrated from Austria.  My father's grandfather immigrated to the United States from Croatia, with the classic case of "one brother stayed behind and the other went to America."  Descendants of the "brother who stayed behind" still live next to the family homestead and I've corresponded with my cousin there.

This is an old postcard of Prezid, Croatia, where my grandfather's family immigrated from during the first part of the 20th century.
I would happily pack my bags and head to any of these places, but unfortunately, travel is expensive and I'm afraid the foreign language would prove daunting.
I would love to hear from my fellow genealogists who have traveled abroad for genealogy research purposes.  Was it as daunting as it seems?