I don’t know about the rest of you, but I have a real love/hate relationship with Gmail. For the most part I love it, but Google seems to have Steve Jobs Disease in thinking that for key features there is only One True Way to implement a feature. If you don’t happen to like that way, Google’s support is happy to post friendly “you don’t know what you’re talking about” responses (see, for example, their responses to the completely screwed up way Gmail will associate completely unrelated e-mails into the same Conversation).
Fortunately, there are scripts and add-ons to deal with most of the defects, such as the Folders4Gmail Greasemonkey script which lets the user organize labels into a hierarchical structure. Google says nobody needs this, but I beg to differ. This is extremely helpful. For example, each of my web sites sends out numerous administrative e-mails which I assign labels to. It’s extremely helpful to have a Web Sites –> websiteX hiearchy, so it’s easy to quickly drill down to these particular set of e-mails without cluttering up the labels list.