8p s3 or b8 a4 avant...practicality

[Alrey87]

What are the s3 sportbacks like for boot space? Currently have a bmw 335i coupe which is not practical anymore. Would prefer something sporty like s3 but also like the look of the face lifted avants, interior looks very nice and some decent engine choices, probably similar price wise but obviously s3 being a lot older and will depreciate less, but also less modern and worse on fuel. Average about 28mpg in my bmw on a motorway run at 80-90 mph and would like to improve on this if possible.