When was the last time you flew through LHR? I think T5, taken alone, is the best airport in Europe, and I'm not sure it is close. The facility itself is really nice, and it has fantastic lounges, shopping, and dining. It is logical and, frankly, pretty well set up for connections. They open the third concourse very soon, and there is the potential for a fourth, which would possibly allow them to consolidate the few destinations flown out of T3, which, while not my favorite, really isn't THAT bad. LHR does have some operational challenges, but they are manageable enough, considering that it is the most valuable O/D market in Europe and in a great position for routing TATL flows. MAD is a nice compliment, and another first-rate facility.

1W certainly has some challenges in the non-TATL market, due to geography, but the ownership of the London market is nothing to sneeze at, nor is what is perhaps the best product offering, save maybe F, of any European carrier.

As to the lesser SkyTeam hubs, OK can't seem to get out of their own way. The location could be useful in the long-term, but I'm not sure OK will ever be able to truly capitalize on it. As for UX, I try to avoid Spanish carriers, so know nothing about them, but would note that they have a very limited footprint, and only a handful of destinations outside Spain.