Documentation doesn not look so bad until you try to dive into the baby.
Well ok , documentation is an important stuff but it is just a matter of time
Same for features
unless the engine is lacking some key feature It does not seem to be a good reason to quit with it
Different story for bugs and I am not speaking of minor bugs
As far as I read with B.V you could not finish even a casual game
Maybe some old B.V. and \ or new GC user can share with us his experience