Frustrating, was once hugely helpful, now NOT Rated 1 out of 5 stars
This add on once worked like a charm, and was the most important tool I used, now it no longer works half the time. It has truly become frustrating. One of the big issues is you can still sort of tweak existing css properties, but you can't add a property, ie; if there's no margin defined you can't add one. Even though it appears to be working in the updater window, when you sync, then when you upload the css file it never updates properly. This was once the most time saving add-on out there now it's dead in the water. My hope is this get's fixed, I would have easily paid more for a version that truly works but as it is I wouldn't bother.
Update: I have now completely reinstalled the application and still it is not working I am using the latest version 1.5 and still it does not work. I am updating this review because the developer made a comment -- and I have now spent a great deal of time trying to make this work properly and still it does not work.
I am sad it does not work as it was quite good when it did -- but having established that the add-on, Firefox, Firebug, and my own OS 10.6.8 (working on a macbook pro and this is as far up as I can update) are as up to date as possible it still is not working!
Don't get it, if you didn't update it must be something with your own setup that changed... To give the app itself a bad rating because of that only makes me NOT wanting to help you.