I have never been a fan of IE8. Most serious developers (web or otherwise) know that it is rubbish that unfortuneately has a very large adoption. I generally do most of my web development in FireFox and use Fire Bug to do my web site debugging and design. I like of course the on-the-fly features of changing and prototyping different web layouts.
IE has always been a pain my side not only because of their refusal to adopt widely used DOM standards but buggy browsers that are impossible to reasonably debug.
Today I needed to verify a layout issue and with my recent IE8 upgrade noticed the developers tools in the menu. I nearly fell out of my chair in shock to see a robust set of developer tools. This was just amazing that I could now do nearly the same things I could do in Fire Bug. I am in no way going to ditch firebug but I now have a rather decent means to debug IE problems specifically.
I could use Fire Bug Lite but I find that it's performance is poor in IE. This does work well however. I imagine that Microsoft is trying to muscle-in on the developer market but I think most serious developers are going to do ground-up development in FireFox.
Chrome is still my favorite browser to surf in. I can't wait till they get the developer tools in it so I can use it for more web development.
Anyhow, IE8 gained a few (very few) points with me today since they finally got some developer tools that actually work.
