Thanks P-P. No doubt the principles of airmanship apply in this case. Also, I'm aware some ports have specific procedures for departures which may discourage/prevent arming vnav for takeoff.
Perhaps I should be asking if 737-400's have VNAV armed for takeoff (an educated guess would be, no). I know the -300 manual doesn't call for vnav until 3000 or above.
Now approaching the veeery annoying stage. I can't find any technical reason for not arming vnav on the 737-800