Hope you guys see the fine points of the review, as the Rip9 is a great do it all bike. I had taken the bike up to Whistler BC, with the hopes of flogging it on the big trails up there, but that did not work out. I had to do all the testing in NorCal, on our 'big' trails. I'm a XC rider, and not a big gnar rider. In the recent year, I've come to really appreciate a All-Mountain bike. I bought a GF Hifi29 18mos ago, and really started to understand the speed I had been missing on certain DH sections. That bike is nice, but not plush on the travel, and too flexy. Keep in mind I'm 155lbs, but push my bikes really hard.
My normal rides are One9 and a Sir9 before that. I sold the Sir9 because of too much flex, for me. I have had the One9 for 2 years now, and it is super bike. I do wish for more frame stiffness, and maybe that's where the Carbon9 comes in.
In reviewing the Rip9, you really have to keep in mind what type of bike it is. On my One9(33x20), no hill is ever too steep(too long and steep, yes, but rarely too steep), and I can virtually hop up on anything. The acceleration is unmatched. On the Rip9, I can sit and spin up the steep and long, and then let go of the brakes, hang on for dear life on the downhills. The 4.5" on it feels a lot like 6" on a 26er. I ride my HT so hard, often with a rigid fork, that a ~3-4" FS isn't any faster for me. The Rip9 is enough of a change, and has enough travel, that I can really enjoy the difference over the HT. I find myself constantly steering TOWARDS rocks and roots, in order to launch off them. It is too much fun.
The Rip9 is really well matched for me, and my weight. As mentioned earlier, the Fox RP23 shocks really can't handle the heavier riders very well, or at least as well as the middle of the range weights. When you have to pump up the shock so much to get the sag where you want it, the compression curve is not very good. I did not test this on the RIP9, but I have set up many bikes for heavier riders and the results are very similar, regardless of suspension design. PUSH will be able to help a little. A DHX air with boost valve would maybe go a long way to help with the last part of the compression ramp. The Niner boys would know much better than I would how the different shocks match up on the Rip9.
If you live in an area that has some rocks and/or elevation, the Rip9 is really hard to pass up.