I remember the metz hammerheads well, they date from a time when AA's couldn't hold as much of a charge and things like nicads were the best we could hope for.
I liked the stability of them, there wasn't IS in those days either...
I generally OC cable or wireless flash these days, but I still have a flash grip which occassionally gets a run out for video.
Canon did do an A-TTL hammerhead which I believe can be used manually with E-TTL cameras, but the speedlite form is just what folks prefer these days.