[citation][nom]killerclick[/nom]I use a lot of browsers (FF2, FF3, O9, O10, Chrome, Safari, MSIE6,7,8, Seamonkey, Konqueror... - as a web dev I have to) and connection speed (latency and bandwidth) are the only parameters that I see having any effect on page loading speed. AJAX itself is just a way to send requests and receive responses from servers without reloading the page and it doesn't affect the loading speed (since the whole point of AJAX is that it's used after the page is loaded).[/citation]
You are correct about AJAX, its just a javascript way to make server requests. But more and more sites are relying on AJAX to provide a more interactive interface for users. I was buying some books off of chapters.ca (Canadian book retailer) the other day and their shopping cart system was very slow to use in FF, so I switched to Chrome and it was much better. Same with another site I was checking out, BookArmy.com. Both use a lot of AJAX (I love the new chapters site) and both are much better in Chrome.
Anyways I do notice an initial load time difference between different broswers, depending on the site. Some sites are virtually the same, but some are quite a bit faster in Chrome.