Go for the Prima!!! Parts are very easy to get because the Tacony factory is in the U.S. The machine was designed and engineered in the U.S. If by some off the wall chance an elbow broke on the power head, it won't cost you $100+ plus like it would on the Meile and I've heard the Miele elbows do break easy. Miele parts and tools and amazingly costly!!
The Prima is whisper quiet, Class A filtration, the bags do self seal-- I've seen with the fancy plastic closure system, and excellent HEPA grade. The wheels are soft gel base off what is on roller blades. Really a cool design!! You and your wife will be impressed, but take her along to test drive it at the store too!