I've had MSII on my 4.6 in a RRC for over 2 years now with absolutely no problems. I bought an assembled one from UK added a toothed wheel to the back of the harmonic balancer, VR pick up, EDIS module, coil packs and LC1 Wideband 02 sensor. No more MAF, no more distributor, virtually runs underwater, even got rid of the stepper motor as the idle is so stable. Easy to tune/fiddle with, just plug in the laptop. I agree that the guys on LR4X4 are very focussed on MSI but I've had no problems with the MSII Extra version.