On large directory structures it takes significant time to iterate through the file and directory counts recursively to get a complete ContentSummary.
When you want to just check for the quota on a higher level directory it would be good to have an option to skip the file and directory counts.
Moreover, currently one can only check the quota if you have access to all the directories underneath. For example, if I have a large home directory under /user/joep and I host some files for another user in a sub-directory, the moment they create an unreadable sub-directory under my home I can no longer check what my quota is. Understood that I cannot check the current file counts unless I can iterate through all the usage, but for administrative purposes it is nice to be able to get the current quota setting on a directory without the need to iterate through and run into permission issues on sub-directories.