I have two issues with search: one is really quick to fix, and the other probably isn't (and I'm not even sure whether you'll consider it a "bug" or a "feature").
First, the quickie: when I save a search with a name having an apostrophe, the link has a backslash-apostrophe instead of just the apostrophe.
The next thing: I use Saved Searches as my own little custom categories, which I think is pretty much how they're meant to be used. I also use a "Project" context for my GTD "projects", and add subtasks to it for Next Actions.
Let's say I want to look at a list of projects, e.g., which are in the "Work" folder and are tagged with "Lab". I can easily get this list with a custom search (and thanks for that, by the way!). However, I can't then see my actions for that project, if I click the link to expand and show subtasks: it won't show them, because their context isn't "Project"!
So, to summarize my second point: in a saved search, you can't view subtasks of a parent task, unless those subtasks also match all the search criteria. This seems to me to limit the usefulness of the saved search feature.