I upgraded to Mavericks. In Safari, when I click on a link and safari opens the link in a new tab, it is slow. There is a little lag when a new tag shows up in the tag bar. If I right click on the link and choose "open in new tab", there is no lag and the new tab opens immediately. I tried this on my friend's new 13 rMBP, it seems to be the same way. If the new link is opened in a new tab, there is always this small amount of lag. Do you have the same experience? I have a early 2010 15 MBP with 2.0GHz CPU, 8GB RAM and 128G SSD.