I don't think the Swift SLX is exactly garage friendly unless you have 9 foot doors (it's 8.6"+ before you factor in the junk mounted on the roof including the 3' radio antenna). I'm 5'10" and didn't have any problems inside of the 184 BH in 3 nights sleeping/showering (with my head in the skylight) but imagine someone over 6' would find the interior required stooping to move around which could be a dealbreaker.
One negative to a higher roof is greater surface area for wind resistance while towing. I brought my trailer home this weekend in a pretty stiff headwind behind my Kia Sorento and it felt like I was pulling a parachute as it is...
Another 7-8 feet of flat surface over top of my vehicle would not have been a welcome change. Interesting that the Starcraft Flight 184bh is actually the same weight as the Jayco Swift SLX 184bh even with the extra 1' overall height difference and fiberglass exterior.