I'd go with the canister
I would definitely choose one of the canister models, but admitedly, I do not like uprights and find that canisters are much easier to clean with.
I don't know much about the home care series, I think this series is only sold in stores and not on line so I'm not sure what advantage they offer if any, although certainly a longer warranty is always good.
I always thought all Miele canisters used the same motor, in the United States it's a 1200 watt Miele vortex motor. I have a Miele C1 Olympus and it's a great vacuum. Although, I think recently, Miele has started using an older design for some of their C1 models, they are made in China instead of Germany and are based on the S4 series when they were out. I think all of the C3 models are still made in Germany.
If you like the idea of a German engineered vacuum and want slightly better quality, you might also consider a Sebo.
Mike