MTAndy - I flew a set of these on a 303 in the hills north of Helena for about 90 days. I came away with this opinion - total waste of time and money.
Now this is only MY opinion based on MY experiance.
Details -
~the longer blades do have more torque, but the air needs rpms and these don't give you more rpms
~the longer blades spin slower than the stock blades at any wind speed under 37 mph
~the longer blades make a different, but no less annoying, noise in high winds - if you are using the internal regulator of the Air it may not be able to handle the torque load of these heavier blades during electro-magnetic braking
~the blades I received were not even close to being the same weight and I spent some hours getting them balanced
~the Air did spin more in lower wind speeds but didn't produce any more usable power at those speeds - for any given state of battery
My suggestion, build yourself a better machine. There are thousands of great ideas on this board and I've made use of as many as I could. Build yourself the machine that is exactly tailored to your location and you'll be happy for a long long time.
I canabalized my 303 and built a 450 watt machine based on the old Windseeker (which was a knockoff of an old Dunn design). It flys and flys and flys and doesn't make any annoying noise. (contact me off-line if you want to know more).
Lastly - it is only fair to say I am not a fan of SWP. I had horrible support from them on the two occations my 303 - pre-blade test or mods - eat it's internal regulator. Some guy named Andy was just an ass. Fair to say I'm not the most pleasent when upset but hey - the customer is always right, especially when he is.
IMT