Meile Guard S1 M1 or L1 cat and dog

These are all for sale at Costco Canada right now (S1 $399, M1 449, L1 499). I have never owned a bagged vacuum and I don't have a big budget but after reading this sub it sounds like it is worth it. I have ~900sqft all hardwood with some cracks and two large shedding dogs. Currently vacuuming daily with a dyson knock off and not picking up much of the dirt and hair.

Questions: is there a big difference in effectiveness of the floor attachments and their effectiveness on hardwood?

Is there a big difference in bag size or how often they need to be changed between these models.

Thanks so much