I disagree. I've used zacks for years. What you'll find are unbiased analyst views of companies. It's like 200 bucks a year as well, so you're not talking big money.
There's a lot to for free on their website. If you don't understand how the zack's rank system works, then you should learn about it first. You can also find some book written about it, but the website will have all the info about it.
You're not going to get a lot with the premium service. Just the industry rank, the ranks of individual companies from 1 to 5, and a snap shot break down of some fundies on each company.
They do have a nice screener as well.
Plus you'll get the trial for 30 days, and you can just cancel and get your money back. The other services they have I wouldn't really reccommend. They're expensive, and I've done them in the past and they did lose money.
But the main point is that if you don't understand how their system works, you won't get much out of the service anyway.