Here is a free alternative, would be interesting to hear if anyone compared the two.
http://css3ps.com/
You get CSS code Instantly In Photoshop with CSS Hat, No Waiting, No ADs. You can choose from 6 CSS formats and CSS Hat has beautiful and easy installation.
It truly speed up your workflow tremendously and users love CSS Hat for that! :-)
The one issue that came up (which isn't technically a bug in your app) is when designing buttons with a default and hover state, you do manually have to tweak the CSS, since the "hover" button won't override all properties of the default one.