Vastly inferior to his 40s and 50s stuff?
I think so. A lot of 60s in general films seem like they were written and directed by someone extremely stoned, and his are no exception. There are long sequences where nothing much happens, or where everything's really botchy and confusing. It's irritating.
His older stuff is much more straightforward and better. Dial M For Murder, I Confess. Complicated but understandable plots.
I haven't dared to watch his final film yet, but I've just realised that the big boxset I bought from HMV seems to be very much late-Hitchcock centric. Which is disappointing.