You can test your site using many browsers and many connection types and locations at the Patrick Meehan test site. Here's a test I ran on you just now:
http://www.webpagetest.org/result/131005_NJ_MK3/
I don't see any real issues there, on this one test.
You can also test your site simultaneously on many computers around the world, here:
http://host-tracker.com/
I don't see any serious problems with your site.