In what way does it 'fail' at bigger repos? It was designed to handle the largest and most complex OS repo that exists.

For me the most amazing thing about git is how it is built out of very simple blocks. Each commit or object is a simple hash of it's contents. Which is just brilliant really. That's why it so fast and avoids any potential data corruption.

Incorrect. OS repos are miniscule compared to gaming and EDA companies with huge digital assets that need to be versioned as well (insert comments questioning why you would ever need digital asset revisioning with code, here).

The killer "feature" of SVN is partial checkouts. If im not mistaken, perforce and bitkeeper have this feature.