I've been using Launchy for several months and I love it. Honestly, I haven't run into anything that I don't like about it or that I'd change. After seeing a bit of traffic around a few other tools, tho, I decided to give another one a chance to see what the competition is like. I doubt that I'll try too many because I hate going thru the install-test-uninstall process. Personally, I'm a screenshot whore. When I look at new tools, I want to see screenshots or demos that show me what I'm getting into. I'm also big on user experience, so anything I use needs to be pretty. Don't get me wrong, function is important, too, but having a good form and function balance is what keeps people faithful.
With that said, I decided to try SlickRun. My first impression was to uninstall it. Well, actually, my very first was to not even try installing it because there weren't any screenshots that gave me an idea of what it looked like. Granted, it's not all that complicated, but I still like to see something before installing a utility. After I bit the bullet and installed it, tho, I was pretty disgusted. The damn thing is just plain ugly. But, since others are praising it, I figure I'll give it a try for a while.
Regarding the capabilities, I have to say that I do like the "magic word" concept. Initially, I was worried that you would be forced to specify all of your words, but luckily it recognizes apps, too. It also supports URLs, which is kind of nice. Those are probably the only two features that'll keep it installed, tho. Given those, now I want a feature to allow me to do what Firefox does with bookmarks: Specify a keyword for a URL and pass a parameter to it. For instance, if I type live michael flanakin, I'll be sent to Live.com with a search criteria of michael flanakin. I love that feature in Firefox.
Anyway, I'll give SlickRun a chance for a while. If only it could look like Launchy...