My old Miele cylinder vacuum is on its last legs. I was hoping to replace with similar, but the old one is 1200 watts, the current Miele models (and other brands) seem to be between 500w and 900w. Is this because they are just more efficient than my 9 year old model, or will I notice a big difference in the suction power from what I'm used to? I have 2 cats and a dog, so need something fairly powerful.