Had the Mace controller on the Magnum for nearly a week...
I will admit that its capable of making the ute feel like its been tuned, and I haven't tried it beyond level 6 yet!
If you're considering a proper tune, don't waste your money, if not, its a great little add on. The iDrive unit does look better, but if you mount it down low and don't actually look at it, save $50 and buy the Mace unit. I found the instructions were a bit generic, but it gets you through mounting and calibration easy enough. I had read the hardest part of installation was disconnecting the factory plug on top of the pedal, used my thumbnail to unlock the orange lock bar and the plug just fell off.
I am impressed with the unit, and the highest praise I can give it, is just to state I have ordered another one for the VE Redline.