I had one go out on me (#5). Went to Z1, had them fix it. Less than an hour of driving later... I notice something strange. Turns out ANOTHER old style injector goes out completely!!! This time its the number 1 cylinder. I think it was already well on its way to going out before this. I also think that uprgrading the ECU put extra strain on an already weak fuel injector. Anywho, I'm now at the same point you are, and I can't justify buying another old style injector. It's on the the new style 555cc's and 300 degree fuel rails. Here's comes my first plenum pull :-)