I have a 17 Octavia vrs estate. And a dog (springer/Labrador cross) – She fits in. We also have a Honda jazz – she fits in that too, but not with much luggage.
Had it after an A6. Boot noticeably smaller, but not yet had an issue taking anything I need – Except for when going away for a week and taking silly things like golf clubs we fill roofbox more than we did with Audi.
Also as above I’d recommend a divider in the boot if you want to carry anything else.
Performance wise I like it. Not silly quick but quick enough for me and much sportier than the A6. Feels smaller (it is) which also helps. Don’t drive it in sport mode much and get c34mpg driving 60 miles a day including some motorway. Put your foot down or put in vrs mode and you can almost see the needle move.
Also had 3 bikes on roof and associated people and kit in car no probs – although as it’s less wide than A6 have to use a lot of the rail (just don’t go too close to trees)