I have used both for emax and the Zubler for zirconia, both are really good ovens and have their strong points. Points to the Ivoclar oven for the clamshell design, it would have saved me 2 remakes that fell off the tray in my Zubler over the 17 years or so that I have had it. They each fire really well with a slight edge to the Zubler in my opinion. They both have a controlled cooling for zirconia so essentially, very similar ovens. I have had one of my zubler ovens for 17 yrs and another for 6 years. The Ivoclar was in a prosthodontist office that I worked out of for a few years and it was 2 years old. No problems from either of the ovens except the input device failed on the one of the Zublers. For me, it all came down to price. Zubler was more cost effective.