Back home after our 2 week Europe 3 generational trip for DD's graduation. I'l try to break down my posts so I don't overwhelm everyone
First, flights.
We did a positioning flight to PHL paying OOP. It's really not worth it to fly in First for such short hops unless you need the extra bags (IMHO). I'll have an allowance of 3 bags weighing up to 70 lbs when I fly up with DD to college, I do figure I can take advantage of 210 packed lbs, lol.
Then we flew direct-PHL-BUD AA Biz (using 330.000 AA miles

). I'd read only negative reviews and it was indeed, nothing great. If I have the miles and the need, I'd do it again, but only if there weren't another option.
MUC-AMS-PRG was economy on KLM. KLM is awesome and I'm always happy when I fly them
in Europe (I've found their premium econ TATL to be meh). AMS is so much easier to transit than CDG. Only downside to AMS is their rough tp, lol.
PRG-CDG on Czech Air economy was the closest I've ever been to flying a LCC. It was a seat and that's it. I'd likely avoid it in the future.
CDG is, in my DD's words, "the 5th ring of he!!." I need to remember why it's worth the extra taxes and fees to fly through AMS when booking Flying Blue in the future. It really does stink (literally and figuratively).
CDG-MUC was on Air France (economy) and they have good service as well. It's really a tie between them and KLM but KLM staff are so friendly, that makes me lean towards them, especially for pm flights. I've had really good pastries with AF on am flights
MUC-IAH was on United and when I went to check in, was initially annoyed that my seat had been changed, until I realized we had a new 767-300 seat conversion to the new Polaris seats. Whoo hoo!!!
This was the best biz product (for only 70,000 United Miles!) and service I've had (and you know I'm a big DL fan). It was really really impressive and I told the FA how much I appreciated her stellar service (anyone who says "I'm not going to let you run out of Diet Coke" is a friend for life, lol). She actually got a little choked up...
Mom and DD flew comfort plus from MUC-ATL on Delta (with Skymiles). Despite a 3 HOUR tarmac delay, they said it was a better product than AA biz coming over (what does that say about AA?). The crew was excellent, kept them informed, fed and hydrated.
So for me, 6 airlines and the best experience for me in business was United while economy KLM>AF>>>Czech Air. Delta first domestic short hops not worth it (to me) but still worth it transcontinental.
Hope this is helpful for someone out there comparing airlines. I have learned that United/URs and MRs stil are valuable for me for flights, AA less so unless I can use them for partner airlines.