I'm not sure what the differences between the two NEW EP's are. Chances are, one just has more bells and whistles but I'm sure they are both equally accurate and they should both produce excellent results. When it comes to Ivoclar's equipment, you're never going to get bargain prices, but you do always get what you pay for. We've got their pressing oven and their Programat porcelain oven, and we love both of them. But... if you're just now getting into Empress, then I believe you'll have to buy one of their pressing ovens as part of the package deal. We did. If not, and you've already got an oven you're comfortable with, then there is really no reason to upgrade to Ivoclars unless you want to. I know of MANY labs that don't use the EP ovens exclussivley for pressing, and to my knowledge they aren't having any problems with the off brands.
There is a HUGE difference in material between the 3G and Empress though. Be prepared for a slight learning curve here. In order to make Empress as pretty as it can be, then you'll want to do the cut back, preglaze and layering technique. They should cover it to some degree at the certification course. If you have any questions though, don't hesitate to ask.
I hope this helped,
Craig