I catch the opportunity to ask a related question: I couldn't find a (simple) way to achieve a tiling effect of an arbitrary object given x and y spacing in whatever absolute unit. This would be more useful when you want a spacing that makes the clones overlap (as in an Escher tessellation) because you can't use the trick of adding a bigger borderless rectangle to obtain the desired offset and deleting it after cloning. Now shift is specified as % of the original object: is that really useful to anybody (I ask to know, not to be provocatory)? Also, I couldn't find a way to ignore border thickness, i.e. using geometric bounding box.
Of course both results can be achieved with some %-math looking at the object dimensions and border thickness but this is not the human way: the computer should work for me, not the opposite!
Thanks. Luca