Hello, welcome to APUG!
With each camera, I would test each shutter speed first. Remove any lens, open the back of the camera, and aim the camera at a bright light, then operate the shutter. Start at 1 second and progress to higher speeds. Each speed should show half as much light as the previous. This isn't a very accurate test, but it's reasonable to do at home.
Also try B (shutter stays open for as long as the release button is held down) and the self timer (wind the shutter, pull down the self-timer lever, press the button).
Next, you should have a lens to test that the aperture blades close to the proper aperture when the shutter release is pressed half-way. The meter should also respond to different light conditions (no battery is needed).
From your description, it seems like the ET would be better, but test both.
Does your ET have a meter? Some do not.