Any opinions on Javascript/CSS minifying gems?

I see asset_packager, jamit and smurf available to handle minification of javascript for production. Any opinions? I am really looking for ease of implementation as what I have is not that complex, just a number of js files and a few stylesheets. But I like the idea of a gem to handle this so I dont have to think about the process once in place between dev and production. Keeping the non-compressed files in development is also very important, of course.