All our Husky stuff is E-Tech except the 365 and the 346. We have them that way because we work in environmental areas so using cats is a good way to limit our impact. They work quite well if Huskys stats are to be belive and of course your breathing the exahust in so the less CO CO2 NOx in it the better. There's more than likely a drop in performance but from my point of view i'd cut 3 seconds longer exposed to 50% less emissions with a good anti vibe system than use a really old powerhorse saw.