It may only be 900cc for that impressive performance, but it also comes down to how that engine was machined and set up. John Doe can buy that engine and set it up for reliability to get 200 hours out of it for freeriding.. where as that 900cc could be running 230psi on avgas with .45mm squish, extremely high advance on the rpm limit and super wide exhaust ports that prompt piston ring changes every few hours, in turn making bucket loads more power than the mild 900cc setup.
With extreme machine work for big power, you could make a 701 outperform a stock, untouched/unported 850cc dasa! ..but you won't get many hours out of it!
You guys believe that the XFS promo vid of a 'stock 701' back flipping was a straight swap from an untouched out-of-box superjet?? ..although I'm not going to doubt rick's unbelievable skill level...