ASP.NET AJAX Perils
ASP.NET AJAX is come a long way since its inception a few years back and my personal take it is that it in a hype cycle right now, where everyone is trying to jump on-board and create AJAX based applications. Needless to say that it has its own benefits, but there definite downsides to it as well. You can read a set of 10 important aspects around AJAX here.
It is known that though it gives a flicker free UX, the under-the-hood story tells a different tale. Having read about it, some days back, we did a small experiment to really see the kind of differences one can get with different approaches and you can read about our findings in this report (Download file). The scenario we took is very simplistic, but the results are still eye-opening.

Comments
I agree AJAX must be used judiciously.
Can you please share the code you have used for validating?
Posted by: Anil | April 4, 2008 01:59 PM
You can get the sample code
here
Posted by: Atul Gupta | April 8, 2008 10:30 AM
Well written viewpoint. The bandwidth savings are well described. Would have liked one more section which gives some description of how UpdatePanel and Webservices invocation works.
Posted by: Vijay | April 22, 2008 09:02 AM
Vijay, I have posted the code also here as reply to an earlier comment. Is there anything else that you are looking at?
Posted by: Atul Gupta | April 23, 2008 04:04 AM