I had an issue with the teflon tube melting in my CR-10, but I upgraded it using a microswiss fullmetal hotend, which at first I was having issues with due to a faulty cooling fan, but since I upgraded the fan with a $20 PC case fan, I have had beautiful prints from that printer. I also upgraded the teflon tube on my other printer, and I haven't had any issues yet.That hot end on a cr-10, I have gone through 3 of in the last 3 months. One lasted 2 years the next one 2 months. I have noticed that if I have my print bed to close the pla will push out the top end of the nozzle if its loose. I will say that I will probably get an other one as there is a new version of it.