Siggi Seuß in Deutschlandfunk reviewed all the new Humboldt books and rather liked "Adventures": 

“And with this we get to the most unusual new book about Alexander von Humboldt … I have to admit that during my entire career as a reviewer I have never come across a non–fiction book that I wanted to explore with such intense curiosity from the first to the last page.”

click here for his piece

And a couple of nice new reviews from last week

“If you’re not going on a big holiday this summer yourself, don’t miss this one. The Adventures of Alexander von Humboldt follow the great scientist, collector and humanist – with all his quirks, his unwillingness to compromise and his visionary understanding of the world.” Der Standard, Austria

“More thrilling than fiction” Göttinger Tageblatt