Will say I've been running these in both 12th and TC... and they are very quick!
I was properly slaloming down teh straight last weekend as it had so much more straight line than anything else
Ok, I know it's not off-road, and Si and Andy are probably best placed to give the settings for that... but they do seem to be very versatile speedo, being able to handle up to 6s after all!
One slight word of caution on the programming card (although this is aimed more a spec class drivers than modified), is that you can't adjust the CHEAT mode RPM range with it, and I've been finding that a very useful tool to tune the speedo to different tracks for 10.5 TC and 12th.
Cheers
Ed