Yes, i have to say, removal of the extensions was a red herring, as was the removal of the VPN client. Recently, I got a new iMac, determined that the problem was some underlying problem that a squeaky-clean manual install would fix.
Well, on a newly zeroed-out hard drive on a blazing fast 2011 imac i5, 20GB RAM, fresh install of Mountain Lion, with just a handfull of run-of-the mill apps (office, iLife, etc.), unpredictably, Safari's progress bar freezes for about 15-20 seconds, then decides to load the page. If at all.
I cannot figure this out. I am on Wi-Fi due to inconvenient ethernet wiring in this room of the house - do others with this problem experience drop-outs and hangs on "hard-wired" ethernet connections? I have had 2 different ISP's in the last month, with the same problem, so I ruled that out.
At this point, I am getting skilled at using Safari until it hangs, then switching to Chrome for the problem site, then switching back. But this juggling act is wearing thin as I await the next Safari update to magically fix this annoying bug, right Apple?