Compared to RCC lounges the T3 :-: and the ARN Scandanavian lounge are all excellent. Free alcohol, salads, breads and soup in the London Lounge, SQ has some hot food (depending on the time of day) and is usually quieter than the London Lounge (unless there's an A380 about to board). All also have pretty good selections of papers and mags. I actually really like the ARN Scandanavian too, never found it overly busy unlike the London lounge and the free wifi works well too. SK flights are a free for all when boarding, make sure you are not last if you've carry on case/s as you will struggle to fit them in the overheads if its busy (which the ones I've been on usually are). On returning from ARN to LHR you do have to give yourself a few minutes to get to the gate as you pass through passport control.