Hi Lee
your test site community page size is around 8mb and on live site its 4mb.
Kindly check both the page and you can compare the requests tools.pingdom.com
Its not the Jomsocial page, all the pages are loading with the same speed. kindly make a test for both site and you will see the difference is the page size most of the request from the template image.
The best way to compare them is to disable all 3rd party extensions on test site and run the URL of the Jomsocial page and compare it with site other pages.



Regards