I find the spam filter extremely confusing with the tag and quarantine things. It's not well explained, and frankly it's not very clear how it works.
On the other hand, I have everything tagged and quarantined at 0 and so no junk gets through. It's a bit of a pain initially because then I have to spend a lot of time white listing but now, finally, for the most part it functions well.
The problem with no tolerance levels is you have to go back and look at the list of emails in the junk folder to make sure nothing was tagged as junk that is actually good mail. This is the most hair pulling, nail-on-chalkboard irritation of the filter because rather than list the junk mails in order of date they are listed in order of priority level. So of 600 junk mails, one that is dated say 3/21 might be at the top of the list, while one dated 3/28 might be at the bottom of the list. As a result you have to go through the entire list every time you check for good email. I have not been able to find a way to change the sort order.