Why I Use Sublime Text
I've always been a vim guy. Try as I may, I just can't get myself to like any full IDEs. I've tried large projects like Eclipse and Aptana and small editors like Blue Fish and even gedit, but nothing has ever made me leave the comforts of vim.
Despite my love for vim, I don't think it's perfect. I'd like something more like a desktop editor with the features of vim. My friends over at Cards.ly (R.I.P.) use Sublime Text 2 and I liked what I saw. Not enough to commit to switching, but I spent some time with it and liked it myself.
Then I bought a Mac. Why does this matter? Well, I never got used to navigating in vim with the letters and such, opting instead to use the arrow keys, as well as page up/down and and home/end. On a mac, the latter keys don't exist, and I find getting the functionality painful. So there were two options; learn to navigate vim with the keyboard letters or switch editors.
I opted for moving to Sublime Text, partly because it looked really nice, partly because it would give me a unified, cross-platform editor, and partly because I knew I could enable some of the parts in vim I've always missed from other editors. So far, I'm sold. Literally, I bought a license and everything.
It wasn't all cupcakes and puppies from the start though. For example, I blew away a directory with a mis-click (there's no confirmation dialog?!). But I quickly got used to it and haven't really looked back. I even forked the coffeescript tmbundle and got it working for in-editor compilation. Check it out!
Sublime is pretty usable out of the box, but there's some things everyone will want to do before making real use of it. The biggest one is Package Control (#7 on that list). This will allow you to install bundles and plugins and such directly through Sublime. This will make i teasy to add functionality to the editor. For example, if you work in node.js, you probably use things like Jade and Stylus, and maybe you work in CoffeeScript. Sublime doesn't give you syntax highlighting or anything for these out of the box, so you could go hunt down the stuff you need and install them by hand, or type in 1 command for each and have them working in a couple seconds.
That nettuts link above has a number of other nice things you can do, but I honestly haven't done most of them. For me, Package Control, the Made of Code theme and some personal settings tweaks and I'm ready to roll. It's a great editor and it's very easy to get used to. If you're unhappy with your current setup, give it a shot, it's free to try so you've got nothing to lose.