He raves about GMail's threaded conversation view - this actually drives me crazy - it tries to do a lot of clever things, but sometimes you get client e-mails which are then forwarded / discussed internally and then everything gets out of step. The only way to have a non-threaded view is to use their super-cut down version. I much prefer the flexibility with Outlook. Outlook also has the preview pane - unless I'm mistaken, GMail doesn't have this option (if it does, it's not very discoverable) and this is also a major plus, much easier to scan and deal with e-mail quickly.
Personally I prefer the folder based approach of Outlook as well compared to the tags / labels of Gmail.
(And lastly, why use Chrome or Internet Explorer, Firefox with AdBlockPlus all the way...)