Regarding the question of whether Waltke and O'Connor is the best or only
intermediate/advanced grammar available, I encourage those intersted to
have a look at Chris van der Merwe et al. _A Biblical Hebrew Reference
Grammar_ just release by Sheffield. Looks very good, and van der Merwe is a
first rate Hebrew grammarian. Waltke and O'Connor has had another
competitor for quite some time in Jouon-Muraoka, Grammar of Biblical
Hebrew.
Ray Clendenen