Previous version behaved as if it had a memory leak. After intensive use, my 4 GB Mac ground to a halt and had to be re-started with the power switch. I have just installed this new version, and have not had enough experience with it to know how it will behave, but initial impression is that it is somewhat slower than previous version. Also, it has other features like WebInspector under "Develop" menu item, and WebSnapper under "File," and I don't know what they all are, nor can I find any clue under "Help." As an aside, as browsers go, Flock is pretty slick, tough Safari is still my default browser. --Steve