I used one off and on for over 30 years. It's an excellent camera, but only does aperture exposure; no manual settings at all. You do get a 4x, 2x, 1, 1/2x, 1/4x exposure compensation dial. Couple it with the lovely Pentax-M primes and you're good to go.
I'm away from mine at the moment, so I can't remember if there's a little telltale window visible in the viewfinder showing the aperture. Read the reviews
here. Good rating of 8.25.
TBF, mine is currently non-functional. It's started to rip the sprocket holes before the end of the reel, and the wind-on lever won't stay in the "stand-off" position required for the meter to stay on. Since I bought it new, I want to get it fixed, but Miles Whitehead said he didn't have and couldn't source a spring for the stand-off lever.