Ok, first things first, obviously they aren't compatible with any other figure ranges, no matter what scale I say they are. In terms of height they are 15mm, but they have the bulk of 25mm figures.
So I thought it might be helpful to post some pictures of my Cuties alongside real wargame figures.
These are 15mm Mahdists from Peter Pig.
Peter Pig again, British for the Sudan. The helmet adds half again to the Cuties height.
The Sumerian battlecart is from Magister Militum.
I think these knights are from Lancashire Games.
I don't have many 25mm figures, this one is from Black Hat Miniatures, their Three Musketeers range.