Thanks for the report.
Any details on the day in Stuttgart?
It's not a bad MR destination, nor a bad long-weekend or vacation destination at all....what worked/didn't work for you there?? Recco's??
Does UA/LH utilize codeshares on Deutsch-Bahn/German Rail from, say, Frankfurt or another city they fly to??
For AA flyers, it's a HECK of a lot better way of getting into Stuttgart than going thru Heathrow and to STR, but not sure if that's an option for the UA/LH crowd or not. If so, it's well worth checking into, since MRs to Stuttgart don't have to be that much of a trying adventure, get a heck of a lot more miles, and yep, Stuttgart is often underestimated in terms of a cool town to hang out in.
Again, not sure of the "UA"/Star Alliance version of a flight into Europe/Germany followed by codeshares on German rail, but if it's an option, I'd suggest looking at it next time.