For those too lazy to look it up themselves, here's the Wikipedia page on it:
http://en.wikipedia.org/wiki/Wesleyan_Quadrilateral
Now, as to my opinion, based on the wiki's description it's just the usual nonsense:
The shape isn't one in which all of the items are equal, the shape is one in which the scriptures take precedent above all else. If something is in contradiction with scriptures, it's wrong. That's the basis of the whole thing. You don't use reason to see that the scriptures are true, you assume they are true to begin with, and as such you might as well throw reason out the window.
You use reason, experience and tradition to understand Scripture - even if Scripture is primary for Wesley it cannot stand on its own. Contemporary Wesleyans have been more willing to suggest that reason and experience have a role in questioning beliefs based on scripture in a similar way to Wesley's willingness for reason and experience to question tradition.
