Duke787

I'm actually in the midst of doing this right now (parents were on a UA flight back to the States and so I now have a longish wait until my SK flight to Oslo).

It's about a 12-17 minute walk from security itself to the United Club (about 10-15 minute walk depending on pace from when you get to the escalator that brings you down to gate level and starts you on the pathway over to 2B).

The AC/SQ lounges are just to the left when you come up the escalator (just to the left of the WH Smith and Duty Free). The United Club is about 1 minute down to the right from the escalator.

Note the LH lounge is back in 2A (I'm headed there last since my SK flight leaves from 2A).

I can't speak to Fast Track but if you are departing from 2A (where I believe all EU flights depart from) you'll want to come over to 2B first (and hit UA, AC, and SQ - AC and SQ are literally across the hall from each other on the club levl) and then make your way back to 2A for your departure and for LH.

I have not finished my journey so can't speak to all of the food but both SQ and UA have both been pretty solid though nothing super fancy (UA is better than any UC I've been to though I haven't been to NRT UC) and SQ is average (though a nice Singapore Sling). Both (SQ and UA) are catered / operated by Sodexho so the Western food is the same, it's just SQ has some Asian options. Both (SQ and UA) have well stocked bars with many more options than you get in the US (everything is complimentary at the UC and it's not the bottom of the barrel swill they have at domestic UCs).

EDIT: It took me 10 minutes to walk from SQ to LH as a fast walker with only my backpack and walking by myself. A big reason for the amount of time it took is the fact that the moving sidewalk only goes in the 2A ---> 2B direction and so there is no moving sidewalk to go from 2B ---> 2A.

LH itself is a perfectly fine lounge to end on near the 2A gates. It's catered by DO&CO so slightly different alcohol and food selection. In addition at LH the alcohol is completely self-service (with no bar for cocktails) unlike SQ (which is self service except cocktails / spirits where there is a bar) and UA (where there is no self-service at all). I had access to the SEN side due to *G and it had a wider variety of food and alcohol than on the LH Business side.

I think in sum I actually agree with many of the other posters here who said UA is the best. For an American, it has the best combination of food that appeals to me and, unlike domestic UCs, a well-stocked, complimentary bar. Definitely check out the others if you have time but if you are departing on UA and you are tight on time I'd spend my time in the UC (unless you really want a Singapore Sling).