I have a parent jira with a few sub-tasks and each of them are added with an estimate time. In greenhopper detail view, it shows a nice breakdown for remaining estimate but not for the orginal estimates (see my screen shot below). As a comparison, jira view has a flag to include sub-task numbers and when it is on, it shows the total estimated (original) which is more clear.

So I suggest to add a down-arrow to expand the estimate numbers for parent and sub-tasks which will be similar to the remaining estimate right below.