For this year, I only plan saver awards (for 2) on UA to CDG with stop over in LHR on the return. Trip plan is: SFO-CDG; CDG-LHR (stop over few days), LHR-SFO. Looks pretty simple. I started the process 7.5 months out for travel this June. First off, the united.bomb could not book my itinerary. I had to call in (cost $15 per pax for booking by phone).
Final itn resulted in outbound - SFO to YYC (long layover), then to LHR (both on AC), then BMI to CDG. On the return: CDG to LHR; LHR to ORD then SFO. This is nuts with so many stops. It was never this bad in the past.
Besides, can't even get two seats together 3 out of 6 flights. With this experience, I rate UA and *A with a "C".
No experience with other carriers so far this year.