I've been fascinated by ABCs (Anomalous Big Cats) for a while now and have a theory or two. Could I ask you two: CupofJoe and Orcadian, are you 'cat' people or 'dog' people?
I have noticed over the years that in a lot (if not most) reports of ABCs the observer always describe them as being 'the size of a small Labrador'. A lot of the people reporting these sightings over the years spotted their ABCs while walking their dogs at night, or dusk, in less than ideal observer conditions.
I am a cat person. I seriously dislike dogs. They scare the crap out of me but I have had cats around all my life. I know cats. I know how they move. I know how they react. I can place them in context. I can scale them in their environment without blinking. I have no idea what size "a small Labrador" is. All dogs over the size of the sort of yapping abomination you can step on look terrifyingly huge to me.
I suspect that most ABCs are normal sized cats, seen in unusual lighting conditions, or situations where surroundings lead to the cat appearing further away (and therefore larger) than it actually is. Like this: