I'm curious why the disdain for combination locks. There are enough
combinations, even with just three digits, 0-9, you get 1,000 possibilities . .
.. who is going to stand around long enough to try to 'crack' that? Far more
likely they would go for a bolt cutters to cut the cable or the hasp.
Personally, I prefer a combination lock -- no need to mess around with a key,
which can get lost or forgotten.
Bottom line, in general, any security measure is really just a way to make it
*less easy* for someone to casually just walk off with it. A determined
individual will have a way or find a way to get past any measure you use.