So Gmail just enabled the new Labs tab under your Settings, in an effort to get some users to try out the experimental features Google is playing around with. One of the biggest benefits, at least for testing purposes, is that you can enable multiple Gmail Labs features at once, whereas Google Search Labs features can only be enabled one at a time. I've done some experimenting of my own with the current features available on the new Gmail Labs, and here's a quick rundown of the best and the worst:
Best
Superstars - This feature greatly expands the options of the gold stars Gmail already offers. There are multiple colors of stars now, so you can assign your own color-coded organization for follow-up emails. Additionally, there are new symbols available, so you can add a question mark, exclamation point, or a check mark to name a few. You choose which symbols to use, under the General Settings tab once Superstars has been enabled.
Quick Links - Bookmarking for your email. Need immediate access to a follow-up email? Create a quick link for it, which will allow you to label the email for your personal references. The Quick Links box is found on the left side of the page, directly under the Labels box.
Old Snakey - Who doesn't love a throwback game of Snake? Enable keyboard shortcuts on your General Settings once you've added the Snake Game in Labs, and a quick stroke of the "&" key will pull up a quick game of snake. We all need mental breaks from the woes of an overrun inbox, so tune out for a few minutes with this gaming classic.
Worst
Mouse Gestures - Between keyboard shortcuts and Gmail labs custom keyboard shortcuts, there's enough going on that's specific for Gmail. Mouse gestures makes things infinitely more complicated by allowing email inbox navigation with the mouse. The main reason this feature makes things more complex instead of simple is because of the varied mouse types that users may have, especially for Mac users.
Hide Unread Email Counts - Being able to hide the number of unread emails in your inbox may seem like another feature that would provide a much needed mental break, but really it's just a cop-out. It's like not checking your account balance while you're at the ATM because you really believe that what you don't know can't hurt you.