Let\'s take a really simple example on using jQuery to ajaxify our page...
$.load(\"getOrders.aspx\", {limit: 25}, function(data) {
// info
Page life-cycle only has meanings in context of page elements (controls), so i don't see any differences in your case, since you don't have any other child controls in your page - this is totally irrelevant.
But here is the real question: if you don't have any rendering of html in your page (only data serialization), why you have choose to work with regular .aspx page?
Web service is ideal candidate for this scenario. And you'll be surprised how much performance improvement you'll gain in the end.