The Nordic Boats 27 Thor 2012 is a catamaran design and the Nordic Boats 42 Inferno 2011 is a modified-V design, so you're likely deciding between two noticeably different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
Size is the most obvious dividing line here. The Nordic Boats 42 Inferno 2011 measures 42,0 feet overall (2011), giving it roughly 14,8 additional feet of deck space compared to the Nordic Boats 27 Thor 2012 at 27,2 feet (2012). Weight tells a clearer story for trailering families: the Nordic Boats 42 Inferno 2011 tips the scales at 11 100 lbs - 6 350 lbs less than the Nordic Boats 27 Thor 2012 at 4 750 lbs. That difference is meaningful if you're working within a half-ton or three-quarter-ton truck's tow rating, especially once you factor in a motor, gear, and fuel.
For family outings this is probably the sharpest distinction between the two. The Nordic Boats 42 Inferno 2011 is rated for 12 passengers, while the Nordic Boats 27 Thor 2012 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Nordic Boats 42 Inferno 2011 could be the deciding factor.
Bottom line: Choose the Nordic Boats 42 Inferno 2011 if your priority is putting more people on the water - it handles 12 passengers and at 42,0 ft it has the deck room to back that rating up comfortably. The Nordic Boats 27 Thor 2012 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.