I'm the one running Revo Stg2+ with completely standard exhaust system.
Reasons for this are 2 fold.
1) Car was purchased through Audi Finance but with a full 30% deposit. Whilst I now own considerably more than half of it, and intend to pay the bubble off and keep it, under the terms and conditions of the agreement of ownership I don't have the same flexibility in terms of my modification path as those who own their cars using a bank loan option. Therefore, other than the air filter, ALL other mods are practically invisible to an initial inspection.
2) Having had a few exhausts in my time, I am now at the point where I am less impressed by the benefits of the new aftermarket systems when compared to the latest OEM ones. Yes they are better manufactured (well in some cases), but at the end of the day no matter what you bolt on the back of your car it still has to get out past fixed diameter outlets in the block. Whilst I accept and appreciate the aftermarket exhaust will be freer flowing at top end, and will assist some heat dissipation, the differences are not as big as some may leave you to believe. There is a lot of hype. When my exhaust gives up (and it will, and prematurely), it will get changed for either a full Pipewerx system, or maybe a Pipewerx DP and cats (with maybe a bypass for outside MoT season) with an OEM cat back. After cobbing out £1100 on a Milltek on my last car I'm in no rush to be passing them any money for this car as I found it added VERY little to the mix. It's no accident someone who had a very quick S3 was running an aftermarket DP, cats, and OEM cat back, as to be honest the OEM stuff is just not that bad anymore - yes it can be improved upon, but lets not kid ourselves here, these are still road cars and not even in the same league as track prepped machines. Millteks seem to be a nicely made product, but these days have become more of a bragging right to people who also have to have coilovers fitted to take their kids on the school run (don't get me started on coilovers!). When it's broke I'll change it, but I won't be mindlessly running to any one brand because I want to give them the best part of a grand or so based on being part of 'the in crowd'. Given the amount of fuel that seems to be popping in the system when you take your foot off the gas I'd say I'll be changing it sooner rather than later.
Anyway, the car seems to be running fine at present, but having said that I have now signed the kiss of doom (commentators curse).
Any maps built to run 105RON in the real world seem largely pointless given you struggle to get a true 99RON in the UK. Must surely be for purist race application. So much of the US figures based on very high octane figures, yet they all run about using 91RON!