Dutch is more precise; there's less ambiguity. You have to think a little more before you speak (thanks to the differing subject-object-verb order). I've become a better engineer since learning it.
We're raising our kids bilingual because the benefits are just so clear; and I figure that if they get English/Dutch for free then German is very cheap so they can learn an east-asian language too..
Really? I would suggest that Dutch is plenty of ambiguity as you can omit a lot. e.g. "Ik moet naar de tandarts [gaan/rijden/fietsen/lopen/bellen/kijken/wijzen/zoeken]" ("I must [?] to the dentist").
In German at least, you tend to use "go by vehicle" where English would just use "go". That is the preciseness English doesn't have.
Interesting that the "I must <x> to the Bla" construct exists in Dutch, English has it, but it's antiquated.
Dutch (like most natural languages) has some ambiguity, but nothing like English. For a start spelling is mainly phonetic (unmodified loan-words excluded).
From the perspective of an English speaker it's a very clear language which is made slightly complex by making most common verbs irregular (i.e. to make speech flow) and having arbitrary genders (de/het).