Flying from London Heathrow's Terminal 3 and got a Qantas Frequent Flyer Platinum card, or the Emerald equivalent with other oneworld airlines such as BA and Cathay Pacific?

There's no shortage of oneworld lounges at T3, including three first class lounges accessible to Qantas Platinums and oneworld Emeralds: those are American Airlines' Flagship Lounge, British Airways' Galleries First lounge and Cathay Pacific's First Class lounge.

But with only a few hours before your flight, which one should you choose?

We've reviewed them all -- and the results of our on-the-ground tests (not to mention our real-world pictures) may surprise you!

The three lounges in a nutshell

The lounges are all fairly near each other in T3's "corridor of lounges" which is so familiar to frequent flyers.

Once you pass through the irritating Heathrow duty-free maze make a left turn for Cathay, go straight on for BA and turn right for American.

BA's Galleries First is the default lounge for most Australian travellers.

It's long but not deep -- around the size of Qantas' Sydney International Business lounge. Pick it for champagne, wine or food, but skip it for business use, natural light or a view.

Cathay Pacific's First Class lounge is a tiny gem, with particularly good work areas and floor-to-ceiling windows.

Veuve Clicquot champagne is firmly business class, although the wine is well chosen. The at-seat noodle bar is a real draw -- there's just something about noodles before a flight that ticks the box.

We'd normally never suggest anyone pick an American Airlines lounge over any non-US airline's facility, but the wifi is blisteringly fast: we're talking 15 Mbps down and nearly 18Mbps up. (That's compared with just under 4Mbps down and 0.5 up at BA's lounge, or 2Mbps down and 0.2 up at Cathay's.)

Speedy and rock-solid wireless Internet is a weakness of many airport lounges and there's nothing more frustrating when you're trying to send or download some large files before your flight.

If you need to be connected and don't care about bargain-basement wine or unimpressive food, this is the lounge to pick.

Who'll like each lounge

Wine and champagne lovers: BA

If you're a fan of wine and champagne, BA's Galleries First is absolutely where you should head.

Current champagnes when I visited were Laurent-Perrier Grand Siècle and Bollinger Rosé -- both well up to the international first class standard.

If you're not a fan of the bubbles, Galleries First is also blessed with some fabulous wine.

Unusually for me, the top three are all whites, although there are also some respectable reds:

• Pacific Rim (Washington state, Columbia Valley) Riesling: off-dry but pleasingly complex
• Morgan (California, Monterey) Sauvignon Blanc: herby, mouth-filling and a real find
• Dom Jean-Pierre Sève Pouilly-Fuissé: oaky, buttery and classic; a must for lovers of traditional French wine

Widest range of table-served food: BA

Table service that's brasserie standard (though not up to Qantas' First Class Lounge standards)? BA Galleries First is the place to head.

If you're in time for breakfast, do take advantage of perfectly-poached eggs. Later in the day, the meze plate is great, and the gourmet burger is also very tasty.

Cheese fans should ensure they don't neglect the utterly fantastic cheese plate on the back page: it's a real gem.

Space to spread out and work: Cathay

Of the three oneworld lounges, Cathay Pacific's is the smallest, but it's full of natural light from windows on two sides.

Noodle fans (who will love the made-to-order noodle bar) aside, the reason to choose the Cathay lounge is its full-sized work desks.

Each desk has a computer, but there's more than enough space (and an easily accessible power socket) to set up your laptop and spread out your work. (Or your noodles.)

Lightning-fast Internet: American

Yes, we're ordinarily as reluctant to visit a US airline lounge as you are. They're normally so far below the accepted international standard that you can barely see them.

But the American Airlines lounge in Heathrow has one redeeming feature: super-fast Internet. 15Mbps down and nearly 18Mbps up is world-class.

The buffet's rubbish and the wine would have me reaching for the softies, but if I needed to download a hefty file you'd find me in the AA lounge.

A shower (and a spa): BA

British Airways Galleries First has the best showers of the lot, with side-jets and decent Elemis toiletries.

BA's Elemis Spa offers facials and massages for passengers in BA business or first class and BA Gold frequent flyers. Sorry, valued Qantas partners, you don't get a look-in.

If you happen to be on a BA flight, though, the Elemis spa has some basic sessions you might enjoy. Don't expect it to be up to the Qantas First Lounge standard. The facials are probably the best of the lot.

Ambience and view: Cathay

Let's face it: sometimes what you need at the end of a London business trip is a decent glass of something, a comfy chair and a view of the sunset (and maybe the oddly calming giant airport fishbowl of planes taking off, landing and trundling around).

For that, Cathay's lounge is my pick. The deeply comfortable chairs by the windows and a glass of Veuve Clicquot is a fantastic way to spend the time before boarding.

Overall pick: BA or Cathay

Assuming I didn't have some serious Internet-requiring work to be done, I'd probably pick the BA and Cathay lounges: BA if I were hungry or fancied a really good drop but was happy with a bit of a dark, closed-in ambience, or Cathay if I wanted noodles and space but didn't need a gourmet experience.

Disagree? Have a special place in your business travel heart for one of these lounges? Feel free to sound off in a comment below!

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