Roman,
The case in which I faced was that of a number of counter bored holes on a plate. To make sure all holes were of the same dimension I use the Selection Panel to select all holes of equal radius. Since I knew how many holes total were on the plate, I naturally wanted to make sure that the number of selected 'equal' holes was the same. The only way that I see to do this is to count the number of child nodes in the tree and then add one for the parent node. For a small number of objects, this process isn't too bad, but wouldn't scale at larger numbers. I think that the actual number should be reported somewhere. If you have the measure tool going, a couple of pieces of information pop up, but not the actual count. Perhaps I am just missing it (Style 2009 SP1)?
As it turned out, one of the holes on my plate was not the same as the others. I was probably experimenting with different screw sizes and forgot to re-adjust the diameter after I was done. If there is a better or different workflow for handling this type of situation, I am all ears.
Thanks.