Good luck getting any info. For some reason I have yet to find anyone with the Unitronic chip for the 4.2 (I have an A6 though) to give me any feedback. Maybe everyone who has the chip is too busy driving their car (because they love the flash so much?) to post any info.

I do get a lot of feedback from people that DON'T have the 4.2. I really hope you get a better, and more informative, response than I have.