I haven't had any problems as of yet (new user). The only issue is the two mats you lay the t-shirts on move when you put the shirts on and take them off. I had to tape the bottom one down to the machine. Helped out. Other then that, great machine!
There is a bit of a learners curve to this heat press. The directions were very limited and most of it was trial and error. I did watch some YouTube videos to figure it out. Otherwise it works great.