I have to say this reminds me of old days when, scaling or no scaling, the word to the wise was, if you want a good kite, get a 12.
This was because 12 was (is?) the most-used
size world wide, so designers started designing a model around the 12 then built (or scaled) around that, and it was more likely to be "perfected" before production runs.
Regarding scaling, in fact, aside from fudge factors and empirically determined correction ratios from prior years' experience, (educated guesses in other words), kites
must be scaled, and then the parameters tweaked away from the scaled dimensions through testing. With experience and some spreadsheets the process may be more sophisticated than a xerox reduction, but it still has a key role in design, even if you call it "modeling" or "art" instead of "scaling."
With the
rpm the most likely explanation seems the 12 was designed to fit a range of use rather than a measurement, and other sizes followed. Whether a 10 or 12 was the original "proto-
rpm" ancestor back in 2008 or so may be hard to guess, but I lean towards the 12 as the original, since the
rpm model was meant to fit between the fuel and the turbodiesel, and the 10 and smaller rpms became more sporty, while the 12 and 14
rpm are definitely a little more boring (sorry!) than the equivalent-sized fuels.
The 10 was able to be made flatter and faster to make it more performance-oriented, since it didn't need to support the line's low end, and in fact, folks have said the 10 was more the "sweet" kite in the
rpm line since it came out.
I've ridden with 14 and 12
rpm, and fuels 9m to 15m, and tested 12
rpm back to back with a 2009 11m fuel and can say 12
rpm is a sweet kite, hair more low end and depower than fuel but similar feel and reassuringly just a little softer. The 14
rpm on the other hand, is no more sporty and fun than my old (2005) 15m fuel, especially if I put the old 15 on 20 or 23m lines instead of the original 27s.
Your opinions may vary, but definitely try 'em before you buy.
