Uses a PX28 battery. I've never noticed a drain problem with mine but
lots of long exposures might be a drain. You can buy these batteries
for less than $1 each on eBay and probably elsewhere.
If you have the metered finder:
Attach the finder before mounting a lens.
If you attach the finder while a lens is already mounted the meter will not
work until you remove the lens and re-mount it. This is normal.
The meter switch is spring loaded. Just move it to the ON position and let it
spring back. Don't try to force it beyond its stop point.
The so-called shutter vibration problem is greatly exaggerated and would only
be noticeable at slow shutter speeds if at all. Just use a tripod and lock up the
mirror when using slow speeds as you would with any SLR.
There is a trick to firing the shutter when no film is loaded. Open the back
and manually advance the frame counter past #1 and close the back. The
shutter will then cock and fire without film. Pentax also made a little tool
to do the same thing. It looks like a coin with a prong attached.
If you fire the shutter with no battery or a dead battery it will partly
cycle and then the camera will appear to be locked up or dead even
after inserting a good battery. If this happens just press the reset
button on the front of the body and all will be well.
Using a P67 hand-held is no big deal. Just like a Spotmatic -- only, uh,
bigger.