The good news is that 2 labs features will greatly improve Gmail search: "Search Autocomplete" and "Go To Label". If you have many labels, it's difficult to find one of your labels, especially if you added the label to the "more" dropdown. "Go To Label" adds a keyboard shortcut that lets you quickly open a label: type "g l" and then type the first letters of the label you want to find.
Gmail integrated "Go To Label" with the search box, so the keyboard shortcut only adds "label:" to the search box. If you don't like keyboard shortcuts, just type "label:" in the search box, followed by the first letters of a label.
The autocomplete feature is not useful only when you want to open a label you've created. You can also use it for built-in labels like "unread", "starred", "chat", "buzz", "muted". Type the first letters of the word "unread" and you should find a quick link that shows all your unread messages.
If you use Gmail's advanced search operators, the autocomplete feature shows common values for the operators. Type the "is" operator and Gmail shows a list of built-in labels.
Gmail's search box lets you restrict the results to messages that have attachments or to messages that include a certain type of attachment. Type "has" and you'll see a list of options that show messages with photo attachments, documents, videos or calendar events. You can also type natural language queries like: "photos", "documents", "attachments".
The search box is now the quickest way to find messages from one of your contacts: type the name of a contact or only the first letters from the name and you can read all the conversation with that person. If you want to restrict the results to the messages received from a contact, type "from:" before entering the name.
The other 4 graduated features have a more limited use:
* "Attachment Detector" shows a warning when you use words like "attached", "attachment" in a message without actually attaching a file.
* "YouTube Previews" lets you watch inside Gmail the YouTube videos linked from a message.
* "Custom Label Colors" is useful if you have many labels and the 24 color combinations offered by Gmail aren't enough.
* "Vacation Dates" improves Gmail's vacation responder by adding the option to enter the first day and the last day of your vacation.