Well, I feel more private... Rated 4 out of 5 stars
I was a bit scared when I checked my Cookie Culler addon and discovered heaps of scary-looking cookies that I couldn't remove. After disablling DNT I could remove them, but they reappeared as soon as I enabled DNT again. Turns out this is 'normal' behaviour, since the addon places some kind of 'opt-out' (or 'good') cookies in Firefox for you. Don't worry that you can't delete them; you want to keep them there. Or at least that's how I understand it to be(?)
It's nice that it lists how many spies it's blocked, giving that sense that it's working.
I do wonder a bit about one of the settings - it seems to show me being 'licenced' to use it for one year from installation, so I hope/assume that will automatically be renewed for free when the time comes.
So far it seems worth the download, It's certainly not caused any problems I'm aware of.
Thanks to the developers.