When I was looking to change, I was considering the Octavia vRS Diesel offering. But the more Octavias I saw, I realised they just look like your normal eurobox car. Very plain, but no doubt functional, especially the boot as you mention. Not sure what spec Civic and Octavia you are looking at, but I seem to remember that some kit on the Octavia (on the vRS at least) were optional extras, whereas they are standard on the Civic.
Obviously, being a Civic forum, most will be slightly biased
, but in balance, I am aware of a few taxi drivers who use Octavias and swear by them, some covering in excess of 200,000 miles, without a hitch.