I've finally watched this movie.
It costed just 100.000 dollars in 1966. It had an extremely low budget. It had few special effects, the sets were poor, the direction and the cinematography were TV-like.

THAT SAID, the lead character was part Kyle Reese, part Uncle Bob.
There was time travel, and there were two Terminators ("Tracers" in the movie) programmed to find the lead character, GARTH A7, in order to kill him before he would alter the past and change the timeline!

Michael Rennie was very charismatic as Garth A7. He's a great actor.

No action pieces, except for the long and excellent final fight between GARTH A7 and the Tracer, which truly reminds of the T-800 fist-fighting with the T-1000.

Harlan Ellison was 100% wrong, Terminator was or seemed hugely inspired by this, not by his 2 Outer Limits episodes.