Are there any differences in intelligence between the various breeds of monitors?

[Choogly]

So far, it seems that all kinds of monitors in the pet trade are treated as if they are equally intelligent.

Some people seem to have guesses about which monitor is the smartest, and I personally believe it's unlikely that they are all absolutely equal in intellect when they vary so much in size, origin, and behavior.

I was wondering if you all have any opinions.