Both the Nordic Boats 27 Lightning 2009 and the Nordic Boats 27 Thor 2011 are catamaran designs, the first built in fibreglass and the second in composite, so the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?
On paper these two are close siblings in the size department - Nordic Boats 27 Lightning 2009 at 27,0 ft versus Nordic Boats 27 Thor 2011 at 27,2 ft. At 4 700 lbs and 4 750 lbs respectively, both sit in a similar weight class - either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.
Both boats are rated for 8 passengers - a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
Bottom line: The Nordic Boats 27 Lightning 2009 and Nordic Boats 27 Thor 2011 are closely matched on the specs that matter most. Test-ride both on the water you actually use, check current dealer pricing, and factor in long-term service access before you sign.