I have been frustrated in Mavericks with safari opening slowly and then sometimes loading sites slowly, though the startup was the worst issue. It was that way on both my Macbook Air and my iMac. The problem went away on my MBA when I installed the Yosemite beta and I only started having the same problem on the iMac when I upgraded from Mountain Lion to Mavericks. I have no idea why it took so long for this to occur to me, but today I suddenly realized that if I did option-d to go to the dock (my choice in keyboard commander) and then did "s" for safari it was faster than if I just did option-s. So then I thought of removing safari from the dock and then going into Applications and placing it in the dock again. This solved the problem of slow startup. No longer do I press option-s and wait for safari to load until I finally just switch windows to find it slowly coming up. I have no idea what the problem was but if you do option-s and seem to wait forever to be switched into safari, try removing it from the dock and then putting it back in again for Applications. This may not help significantly if your problem is just with some sites loading slowly but it may help if your problem is mainly with opening safari. ( -- Cheryl I tried and tried to turn over a new leaf. I got crumpled wads of tear-stained paper thrown in the trash! Then God gave me a new heart and life: His joy for my despairing tears! And now, every day: "This I call to mind, and therefore I have hope: The steadfast love of the Lord never ceases; his mercies never come to an end; they are new every morning; great is your faithfulness." (Lamentations 3:21-23 ESV)