I have actually had my fair share of leaks at the two bolt flange at the bottom of the UP. But it started because I used a copper gasket and then I wasn't torquing the hardware enough. Finally a Grimmspeed gasket and lots of grunting got 'er done. And I won't go into my leaking bung issue that had me removing the PS header repeatedly.
Definitely get it installed right with a new Grimspeed (or OEM) gasket and get one with perfect fitment if you go solid.