I got my RF9 combo w/ interlink dx controller today. Only improvement over RF8 so far is the new Interlink DX controller. It is very nice.
However, one warning for those who want to buy just the controller to use with RF8. You need to remap everything and so far I cannot assign 3 modes to the top left 3-way switch (always been my flight mode switch). I can only get normal and idle up 2, no idle up 1. The controller setup in RF8 does not appear to recognise 3 points on this switch. This works fine with RF9 though.
I need to remap and recalibrate this controller for 'all' the other sims I have previously used my Interlink Elite controller with. Bit of a pita but no real big deal. I've managed to remap/calibrate everything ok with Aerofly RC8, no problems. Since there is absolutely no VR improvements with RF9, Aerofly RC8 will continue to be the main one I use for VR.
Edit; I forgot to mention that I could not finish the RF9 installation with the DVD's. It kept hanging part way through downloading RFV9_3.dck. I finally gave up and downloaded it from the Realflight Website; realflight.com/dlrf9/ . This did not take too long to download and it all installed fine and allowed me to register/update, no problems. Looking at the DVD itself it appears to have a few damaged/bubbled spots on it.