For a number of years I have been using Ken Ferrell's (bitshird) Woodchuck Pen Pro for all my pens, using Global Toolings R4 15mm inserts, with great success. I recently purchased the Magic Skew, and let's just say I still learning with it. Right now I using it to round my blanks to about 1/16 inch proud, and then I switch to the Pen Pro to finish off. I am experiencing chatter, especially when turning right to left. Not as pronounced left to right. I have one of Rick Herrell's flat tool rests, and I have it set so that the carbide insert is slightly above center. FWIW.
John