PR is out of the game and I gotta ask you how are you checking if a Link is good for you or not?(If you are not doing this you are crazy)
I am using CF/TF right now for checking the quality of the links and the spam score. It rocks for me.
The cool thing, is if you dont know about them at all, I would make you understand basic things for these metrics.These metrics would help you understand the authority of a site/blog or back link.
CF: Citation Flow
Citation flow is about the No of back links pointing to that domain. Its not concerned about the quality of the linking domains.
TF: Trust Flow
Trust flow is about Trust. Its all about the Quality of the links pointing to that site/blog.
As you can see, if you increase the no of back links to a site/blog, You can increase the CF. So its possible to manipulate this metric. But its nearly impossible to manipulate TF ( Trust flow metric) as its about the quality of the linking domains.
So the TF/CF ratio should be as close to one as possible. This is most desirable. Avg TF/CF comes around .5o for normal sites.
If there a big gap between TF and CF numbers, its easy to understand that, the site has been blasted with low quality of links. It should get more authoritative and trust worthy links.