The Kitchenaid Tilt-head can definitely struggle with making dough. They can bounce all over the place. The bowl - lift has the fixed motor, so you don't get any of those issues. We were mostly using ours for cake and buttercream, but it still needed small adjustments all the damn time. You'll also likely find that you need to buy a kit like this one. For some reason, kitchenaid stopped adding these parts to their machines, which means the attachments are more likely to scrape the bowl, and you end up constantly trying to adjust the tilt head so it doesn't scrape or bounce (see also - the Dime Test) I also had the juicer attachment and the all metal grinder/sausage attachment and to be honest, I don't think they're better than equivalent dedicated appliances. The height of the attachment ends up being very high compared to the bench. Ok for occasional use. In NZ, think you have the similar availablity as Australia, so you should also look at the Kenwood mixers.This hilarous review from Tigga Mac is pretty accurate - the Kitchenaids are better looking, but functionally, you might get a bit more bang for your buck from a Kenwood.
