I agree completely.
I barely made it through 'Stranger', but it was the book that transformed Heinlein, in the public eye, from a "young adult" author to a bona fide novelist who could make sci-fi palatable for adults by throwing a little sex in there.
As far as I'm concerned, books like Starship Troopers, Double Star, The Door Into Summer, Tunnel In The Sky, The Puppet Masters, Fifth Column, and a dozen or so more from that era were Heinlein's masterpieces. Most of his stuff after and including 'Stranger' didn't measure up, in my opinion.