When I started on the RPMs I felt that the struts were relatively soft even with 8-9psi. After a while I stopped worrying about it and I only use the clips in outgoing current, cross-off, or storm conditions.
Some kite designers recommend for their kites that the struts should be rock hard. These tend to be "high performance" kites where the struts have very narrow diameters. Another reason was that the early bow kites could invert if the user sheeted out too much and inflating the kites super hard stopped that problem somewhat. The original Turbo Diesel was one of the those kites
Sorry about that... The link was cut off. But all you need to do is go to www.slingshotsports.com and look for Kite Knowledge Center section of the site. It will be on the main page. From there just pick Kites and then pick RPM. Anything regarding the RPM will be in there. Cheers.
In the end I think you need to find a kite that performs how you want it to. The RPM, and the Rebel, for example, are two very popular kites, but they fly very different--by design. What's better? What do you want/like? Upwind racing, long floaty jumps, super rigid, efficient wing-like feel = Rebel. Softer, deeper in the pocket, more nimble = RPM.
You can make these sorts of comparisons all day long between any two kites. Are three struts enough? Yeah, for me, 100% enough. Would three be enough if I was course racing? Nope.
After flying my 10m RPM today and watching a 17m Cloud buzz around yesterday, I'm partially convinced that I could close off my strut valves and fill only the RPM leading edge to 9.5 psi and still have a very fun kite. Guessing as LE tech gets more advanced, struts will be a thing of the past, or at least a small part of kite physiology. Some cool vids in this post! Loved watching that 6m RPM buzz around at it's low end. That's my mission, find the smallest kite I can use with an honest surfboard. With aggressive flying, unhooked precision, and solid board skills, it looks as though you can extend the low of of a kite by 3-5 kt. Meaning at 90 kg, on my 6; 4" surfboard, I'd be able to use a 9m Fuel or 10m RPM in 14-15 knots.........