For my 2 cents, a CB summary is pretty useless to me as well, since I don't have DDI. I would prefer to see at least the basic math for a character spelled out, especially for higher level characters - it simplifies things a lot when checking a character by hand if you only have to do the math in your head, as opposed to remember all the numbers for the math as well. Like cov said, even if it's as simple as "19 AC comes from 10 + 1 (level) + 2 (heavy shield) + 6 (chainmail)", though standard format is always good.
The google docs spreadsheet sounds good, though it would be nice if the template wasn't changeable for each character's copy. (IE - like the templates in our current wiki. Anyone can change them now, but if they do it screws up everyone's sheet, not just theirs.)
That said, I don't mind if there's no auto-calculation in the math sections, just as long as the numbers are there. If I have to spend 3 seconds adding up your AC with a calculator, so be it
As for which summary block format I prefer ... aesthetically I don't really have a preference. Though if we have to move all the sheets to a different wiki anyway, and the LEB one is more easily scalable and flexible, then I don't see any particular reason not to switch.