I bought the silver and ran for two months (forgot to cancel after the first month) I started off unimpressed as the articles and other content has been pre-generated and wasn't relevant to my keywords. I ran the service to some medium level competition terms to a site that was getting no traffic.
Its the end of my 60 days today and the site has shown a consistent increase in ranking, traffic and affiliate sales. Right now Nuke4me paid for itself so I'm going to sign up again.
I also ran nuke4me for a few clients sites for extremely competitive keywords. I didnt see as dramatic results, as expected, but would recommend this service for any mid level keywords your targeting.