I agree with your statement on performance, but the game changing part is the size of the cabin compared with the rest of the specs of the aircraft... since there is no carrythrough spar and mounting structure on the aft fuselage for the engines, the cabin is comparatively massive for the class of airplane. It also has a supremely trick laminar flow/quasi lifting nose.
And ya it's taken them a long time to go from paper to full certification. But the first few years of its life, all it was was a technology demonstrator... years into its life did they decide to develop it into a saleable product. And in that time they not only developed a plane but an entirely new engine as well. The program has the megabucks of Honda behind it (see excellent place to hide automobile profits). Name any other company new to the airplane game that has taken a clean sheet jet and taken it to certification any quicker? Sino_Swearingen? Eclipse? Hell it took Beech/Rathaeon just as long to make the Hawker4000.
And lastly, this is just Gen1 of the a/c. Once its a proven concept they can scale it any way they want and improve on the technology. And if you've ever owned a Honda motocross bike or ATV, or even a Civic for that matter, you would know that Honda is known for supreme build quality in their products. I'd say that within a few years of EIS the plane will be receiving rave reviews from its operators.