I posted before that I went with the Hatch because I needed the Storage. Coming from a Grand Cherokee it matched up better for my needs. It's usually just me and maybe one other person, so back seats always down so I can carry all my toys like Clubs, Pitching Machine, volleyball set-up, etc.... Or I use the back for computers and 18 gal storage bins for working.
A sedan couldn't handle those needs.
BUT.... I just took a trip to Great Wolf Lodge. Only 5 of us (2 Adults, two teens and a toddler). With just 2 days worth of stuff, and the back floor removed, that rear end was packed to the top as well as under the toddlers feet. If we were to go somewhere for any longer, we'd have never had enough storage, unless I put on a roof rack or had a trailer. I don't think a sedan would have helped me here either.
I'd love Swordsmith's version of a Sonic wagon, but until it comes along, I think I am going to upgrade to a Trax (LT w/roof rack) within a year. Possibly a Subaru Wagon...