I haven't had CE3s, but I bought 3 CE4s and like five or six replacement heads and they all tasted foul and burnt. I probably wasted at least 15ml - 20ml of
juice by trying them out. I could never get the burnt flavor to go away.
Now I'm using Kanger T3s. I had one start to give a burnt taste, but I gave it a good cleaning and did a dry burn and that took away the burnt taste. But, I could never get the CE4s to stop tasting burnt and nasty and foul and all things bad, even with washing and different juices. I finally decided to stop wasting
juice and anger on 'em.
I have no answers, but plenty of sympathy. Good luck!