that's a great one, was around in PhpStorm 7 at least. Also, the Add to Watches is pretty awesome. Great to keep track of the data you care about in a sea of data you get from it.
Careful with Evaluate Expression. Some expressions you can run will kill the apache process and make it so that any other debugging will fail. Usually not a showstopper as you can refresh the page and try again, but worthwhile to not that these evaluations are not sandboxed.