But Gmail does have "folders". Look to your left side panel - the one that says "Labels". Now click on any of those labels - you just opened a "folder" with all the emails that have that label, no clutter at all. How is this different in ANY way from a folder? You must MOVE an email to a folder - in Gmail you APPLY a label to an email... one action in both cases. You can set it up that some emails go directly to a folder - in Gmail you can set it up so certain emails automatically get a label... equal. You don't have all folders open all the time - you open one folder at a time... in Gmail, same thing - you want to see every email in a given "folder" (i.e. with a given label), just click on that label in the side bar... side bar with folders in other systems... so again - equal. What exactly is different? Inbox? You can archive stuff in Gmail so it's not in the inbox - problem solved. Really, it's just a different way of thinking, but you can accomplish exactly the same thing - and IMHO, easier in Gmail. Oh, and btw. they recently introduced a ton of new ways to individualize labels. Way more flexible than folders IMHO.
On topic - yeah, I'm a Gmail fan, used it since early 2004. My favorite email service. I've used hotmail since before they were bought and murdered by Microsoft. Once Microsoft bought them, they went downhill. I've had that account hanging around gathering spam since forever, but in the last year or so, lost track of it, so I think it's gone. I hated what it became. Yahoo is better, but still nothing even close to Gmail. Oh, and I never use any email client - like Mail - I only ever do web-mail access online.