The business class travel experience isn't all about spacious lie-flat seats, bistro-grade meals or extra-attentive service.
Almost without exception it begins at the airport, with a business class lounge to while away the pre-flight hours.
(In fact, for an increasing number or airlines including Qantas, Emirates and Etihad, it actually begins before that, with a chauffeur service from your home or office to the airport.)
Access to business lounges is one of the most prized and practical perks of travelling in business class or being a frequent flyer with suitable status on your shiny membership card.
Upgrades? These days they seem few and far between.
A higher checked luggage allowance? Many business travellers pack light, and quite a few survive just with carry-on bags.
But being able to escape the massing throngs of the airport for the seclusion of a business lounge, even when you're flying in economy, is something to put a smile on every traveller's dial.
I'm deliberately stressing business lounges here, and drawing a line under the more exclusive environs of the first class lounge.
After all, access to first class lounges is far more limited than a business lounge, and the airlines continually strive to top each other with the likes of day spas, five-star dining and private rooms.
Business lounges don't enjoy the same degree of indulgence from the designers and bean-counters.
But that still leaves plenty of scope for some superb lounges dotted around the world.
Here, in no particular order, are five business lounges which are really raising the bar.
Most of them aren't even located in an airline's home city, which is where you typically find the best lounges, but at other airports in the network.
1. Qantas Singapore Lounge
Following the shift of its primary Europe-bound hub from Singapore to Dubai, Qantas replaced the separate first class and business class lounges in Changi Airport with a single integrated lounge.
The Qantas Singapore Lounge borrows from both first and business lounges, with a buffet plus a la carte meals from Neil Perry's Rockpool group served in a hawker-style environment.
Add a well-stocked cocktail bar and a variety of lounge seating with no shortage of powerpoints, and I'd rate this as one of the world's best business lounges.
2. Virgin Atlantic Clubhouse, New York
Virgin Atlantic doesn't fly a first class cabin – its Upper Class is a cross between first and business – so its Clubhouse lounges also straddle the class divide.
But Virgin's lounge at New York's JFK airport doesn't lose much compared to its flagship sibling at Heathrow.
You still get the spa and Bumble & Bumble hair salon, a cocktail bar that holds its own against the hippest NYC watering hole, a brasserie stocked with top-notch nosh, and a pool table.
3. Star Alliance business lounge, Los Angeles
Part of a recent trend towards airline alliances opening their own lounges, Star cut the ribbon on its latest Star-branded airport lounge last week at LAX.
The lounge is open to all business class and gold-class frequent flyers travelling on Star Alliance airlines flying out of the Tom Bradley International Terminal – which includes ANA, Asiana, Lufthansa, Singapore Airlines, SWISS and Thai Airways.
Contemporary LA-inspired design and decor tips a hat to the lounge's location, while an outdoor terrace dotted with cosy fireplaces offers a view across the airport to the Hollywood hills.
There's a second indoor terrace overlooking the inside of the terminal, a quiet 'reading room' with sliding sound-proof doors to insulate you from the rest of the bustling lounge, plus powerpoints and USB ports sprouting from just about every table and sofa.
4. SkyTeam Exclusive Lounge, London
Like the larger Star Alliance, SkyTeam is also forging ahead with DIY lounges shared by its member airlines.
London's Heathrow Airport is home to the first of these, with another due to open in Sydney by the end of this year – and the London lounge provides a hint of what's in store.
This impressive two-level facility goes beyond the usual selection of free food and drink, dedicated workspaces and showers to include a quiet area with day beds, an impressive wine bar and an oxygen bar. (Yes, you can grab a pre-flight hit of O2 in a range of flavoured scents.)
5. Cathay Pacific The Wing, Hong Kong
I'm bending the rules a bit by including this business class lounge from Cathay Pacific's home hub, but this one holds its own against many first class lounges.
Indeed, many guests at the adjoining Wing First Class lounge skip through to enjoy the spacious Noodle Bar, which serves Chinese buns or 'bao', along with made-to-order noodle dishes.
There's also the Long Bar (aptly-named, as it stretches for 23 metres) and The Coffee Loft, where travellers can enjoy barista-pulled coffee and a pastry baked in the lounge's kitchen. In the evening, cocktails are added to the coffee menu.
What are your favourite business class lounges, and what makes them stand out from the crowd?
David Flynn is a business travel expert and editor of Australian Business Traveller.