I totally understand this perspective. FWIW, we're trying to be as open as we can about those "gotchas". You might be interested in our:
- Known limitations (http://foundationdb.com/documentation/beta1/known-limitation...)
- Anti-features (http://foundationdb.com/white-papers/anti-features/)
- Performance considerations (http://foundationdb.com/documentation/beta1/developer-guide....)
Talk to you in a few years :)