I picked up my Schaffhausen-serviced Ingenieur and the folks there did immaculate work.
The crown before servicing (and before slipping off) would unscrew itself every now and then and after servicing it feels tighter when I screw the crown in. I get the feeling it won't unscrew itself again.
Now for the carbon fiber case - WOW is all I have to say. Before serving there were very fine micro scratches here and there. On the lug at 5 o'clock a small chunk of resin had chipped off, exposing the carbon fiber underneath. Even though exposed carbon fiber is ok and tough enough for every day use, it's just not nice to know the resin chipped off.
After servicing, Team Schaffhausen basically filled in the exposed area with resin, buffed and did whatever magic they did and you cannot tell a piece was ever missing - the new resin perfectly blends in with the old resin and there are no lines or uneven marks to tell that resin was added to that area. In addition, the micro scratches from before have also been buffed out/erased away.
After receiving my watch and sitting at the boutique with the lights overhead, I thought it looked a little different - a little "smoother" than before and so I was really surprised when I realized it was because all the micro scratches had been smoothed out, so there weren't awry reflections coming from the case.
Team Schaffhausen really surprised me with how much maintenance work and effort they used, especially since I was not charged for the servicing. The issue was only a crown that slipped off and they could have just fixed that - but they didn't - they also cleaned up the case and the work on the carbon fiber case they did really makes me as the owner of this watch appreciate and like IWC even MORE than I did before. The three months that me and my Ingenieur were parted was worth it. Thanks a lot IWC!
Also I'd like to thank Gloria at the 1881 flagship boutique in Hong Kong for the help in getting my Ingenieur back to racing status again!