Marcus Baker - Listen kids, AJAX is not cool:

“If you writing a user interface, make sure it responds in 1/10th of a second. That’s a pretty simple rule, and if you break it, you will distract the user. […]

Suddenly we have lot’s of web developers “enhancing” the browser experience with behind the scenes XML fetching back to the original site. I cannot think of a worse collision of technologies than low level user interfaces with requests over the internet. The delays and failures of internet traffic are especially painful in this environment and, from the AJAX demos I’ve seen, the developers aren’t helping. […]

I don’t think I am alone in being habituated to the way the web behaves as pages. When you write AJAX applicatons you drive a horse and cart through one of the most successful metaphors of all time.

AJAX has possibilities, but it’s not there yet. Not as a community and not with the tools. Web developers cannot become GUI developers overnight. We need time.”

Ajax Blog has a good follow-up - AJAX: telling it like it is…:

“The more I think about it, the more it’s clear that some kind of delaying HTTP proxy, that I was suggesting here, is badly needed to make people see how badly AJAX can suck when you inject a little latency - AJAX@localhost is always going to look good. […]

From where I stand, Javascript is today where it should have been about 5 years ago as people were discovering DHTML - you can now write code which has a pretty good chance of running under all the modern browsers for the sake of neat web page gimmicks. But what Javascript isn’t is a sane environment for building MVC applications where the data model is available courtesy of AJAX. […]

Of course this not going to stop anyone from trying - we’re talking holy grail here. But what is worth remembering is if you decide to go AJAX, realize that you’re significantly increasing the risk that your project will ‘fail’.”