Hi, 
I'm an experienced home cook and baker, and want to buy a Kitchenaid stand mixer, But I'm a bit confused about the different models. 

The information in the company's website is quite lacking, and the model names different than those used in my country, perhaps because they're older models or something? 
Different websites give different data about the models to add to my confusion. 

There isn't much choice where I live, and I need a strong, durable one, to work hard and last for many years, so the decision came down to choosing one of two models: 
One is the heavy duty 5KPM5, Which I gather has a 0.625 hp and a 5 liter bowl. 

The other, probably newer model: 5KSM7580, which I gather has a 1.3 hp and a 7 liter bowl, so is also larger in size, and costs a LOT more. 

I couldn't find any more differences between them, but I might have missed them. 

Do you think it's worth paying the extra cash for the more expensive model?