After enduring the stock avid 4s and switching to BR550s (mild improvement) I still had poor braking and extreme fork juddering (outright hazardous in the wet). Had given up and was about to sell my JTS. Instead, I took the plunge and got tektro mini vees installed. In a word: AWESOME! Powerful, good modulation, no squeaking (yet) and no freakin juddery fork syndrome at all. No need for travel agents, same clearance as the canti's I had. Run, do not walk, to your LBS and make the switch!
Thanks to Elmar and others on this forum for encouraging the move