Sorry for very belated response. I think I had notifications turned off.
Could you provide some examples as to what specific labels and character string you had that gave the feature a much needed place in your priority system?
Descriptions like these often make sense until I try imagining what specific string I would use.
Well, the example would be anything you could imagine, I suppose.
For example, suppose that you had (say) 500,000 records (notes) in your database, and wanted to be able to flag any notes that contained any reference to "caffeine".
You set up a sub-category in the hierarchical category tree under "Hot drinks", and set the rule that any future occurrence of "caffeine" in any new note will be auto-assigned to this category.
Then you realise that you might want to do this for all 500,000 records in your database, so as not to miss any references to "caffeine", so you set a rule that this category association is to retrospectively run once.
Then someone asks how many such references have we had in notes created after 2010-05-02, so you set a conditional "date >2010-05-02" category, and retrospectively run it once, and add the rule that this category is to be auto-assigned in any new notes.
You then do the same for "Milo" and "Hot Chocolate".
And you can individually view the filters for "Caffeine", "Milo" and "Hot Chocolate" after 2010-05-02.
Then you might want to see how this is consistent with the parent "Hot drinks", so you view that list of filtered records, and it shows all records created since 2010-05-02 which are assigned to "Caffeine" and "Milo" and "Hot Chocolate".
As well as doing this, you might want to now set an action priority, so you set up a parent group called "Priority", with subgroups A, B, and C. You then go down the list of records assigned to "hot drinks" and flag them as A, or B, or C. Then you notice that one of the C flagged items should actually be a B, so you change it. That record pops OUT of the view of the C items, and INTO the B list.
By the way, I spoke to soon about GTD for Gmail. It's all good. The improvements have not reduced the functionality. All you have to do is set up what you want via the GTD Preferences section.