I just got both of them (RPM and Enge 09) and I have to say that Edge seem much more pros then RPM. RPM seem to me as old-fasion style kite, seem to be very hard to destroy but also very fat and thick. Also just pumped-on Edge is slimer, longer (it's 11m but almost 1 meter longer then RPM) and seems to be much more styled for wind. Also as I tried it it's unbeliavable fast and strong.
I'll give a try to both but currently I wouldn't buy RPM just because it's shape is not so good (meaning leading edge) then Edge and also built quality (seams, one-pump system, etc.) is way ahead of RPM.
I have photos where you can see what I observed so fat at my flat, focused for design details.http://jestercichlup.compoundev.com/down/SSRMPvsOzoneEdge09.zip
Let's see what will happen when riding because I just don't believe that RPM can be better and faster then Edge right now. Looking forward for the weekend session