I've got quite the problem and I've been digging into it for a while.
I am on a MacBook Pro Retina, 2.7 GHz i7, 16 GB Ram, running Mavericks (10.9.1).
This is a work computer that was brand new in October.
It doesn't matter what browser I use, I've replicated it in all of them, but I am mainly using Chrome.
I've done some digging in chrome://net-internals/#waterfall to see the events and in hopes that this is a low enough level to see what's happening. Here's the request info that seems to be where it's hanging:
t=11527 [st= 3] -HTTP_TRANSACTION_SEND_REQUEST t=11527 [st= 3] +HTTP_TRANSACTION_READ_HEADERS [dt=3091] t=11527 [st= 3] HTTP_STREAM_PARSER_READ_HEADERS [dt=3091] t=14618 [st=3094] HTTP_TRANSACTION_READ_RESPONSE_HEADERS --> HTTP/1.1 200 OK Server: cloudflare-nginx Date: Thu, 06 Feb 2014 20:44:23 GMT Content-Type: text/css Transfer-Encoding: chunked Connection: keep-alive Last-Modified: Thu, 08 Nov 2012 11:09:49 GMT Cache-Control: public, max-age=2592000 X-Cacheable: YES X-Varnish: 1986924772 1986903606 Via: 1.1 varnish age: 0 X-Cache: HIT X-Cache-Hits: 5 CF-Cache-Status: HIT Vary: Accept-Encoding Expires: Sat, 08 Mar 2014 20:44:23 GMT CF-RAY: f8aad98b6f109be-ORD Content-Encoding: gzip t=14618 [st=3094] -HTTP_TRANSACTION_READ_HEADERS
This is a pretty quick example as you can see it's only 3 seconds. But this is on one request and most of the time that number is usually over 10 seconds.
Any ideas? I've done a repair of Mavericks but it's still having the problem. After a reboot the problem doesn't seem to be as bad but it's hard to say 100%. I've talked with the IT support at my work about it (it's my work computer anyway) and they have even less ideas.