Using the PN-11 is certainly better in some respects to using the TC-200. The TC-200 should give you more light loss and could decrease image quality depending on how good your sample’s glass is.

That said, the TC-200 has a couple advantages in that it gives you more working distance at max reproduction, and you can still focus to infinity when using it (though that makes no difference for macro work, obviously). I do sometimes use the TC-200 instead for extra distance.
Tiny link: http://taii.cc/54