Suck in your cheeks and pack your best model pose: one of the hottest travel trends of the moment is hautel couture. The world’s leading style gurus have started to team fashion labels with fancy lobbies and have opened a catwalk’s worth of designer hotels.

One of the first to throw his tape measure into the ring was the celebrity milliner Philip Treacy, whose legion of fans includes Stella and Madonna, and who famously managed to transform Camilla into a glamorous bride. He is the creative force behind the 101-room g hotel, which has just opened to rave reviews in his native Galway.

Granted, the man can handle a few feathers and some sticky-backed plastic like nobody’s business, but would you trust him to turn out a decent eggs benedict for breakfast? Well, relax. The big myth of designer hotels is that said designer has anything to do with running them. Treacy’s name may be the crowd-pleaser being shamelessly touted in the publicity material, but the ambitious young Irish company Monogram Hotels is in charge of operations, and will pocket the profits.

Similarly, you might be surprised to learn that the undisputed king of understatement, Giorgio Armani, has chosen the bling capital of the world, Dubai, as the flagship location for a planned portfolio of 10 Armani hotels and resorts. But it all starts to make sense when you appreciate that Emaar Properties, a giant Middle Eastern developer, holds the £572m purse strings.

DOES IT matter? As these hotel groups can be trusted to deliver a professional service, why should the customer care? Perhaps we needn’t, although the chains don’t always appear eager to shout their involvement from the rooftops. Bulgari, the luxury jeweller, opened a fantastic property in Milan last year, guided through the hospitality minefield by Marriott International. But although Marriott’s involvement is acknowledged on the hotel’s website, I’ve heard staff are instructed to avoid mentioning it.

Another concern is that brandscape may be compensating for landscape. Without the Treacy tie-in, try selling The g as glamorous, given that it is in a converted office block in a charmless, out-of-town business park. A neon sign in its luscious midnight-black marble lobby declares “This Must Be The Place” — almost perfectly echoing my thoughts as the taxi turned in (as in, “This must be the place... so why do I feel like I’m checking in to a Carphone Warehouse?”).

Inside, my furrowed brow was soon soothed. It’s very flamboyant, a cut-no-corners movie set of epic proportions. The Pink Salon with its bubblegum-bright walls, Andy Warhol camouflage fabrics and black-and-white vortex carpet is mesmerising, and the Grand Salon’s platinum-blonde crushed-velvet chairs, tables filled with thousands of twinkling Swarovski crystals and a stunning ceiling installation of gleaming silver balls is a supreme Ziegfeld Follies moment.

There are Connemara-bred seahorses in the fish tanks and the top suite is named after Treacy’s good friend Linda Evangelista, after she pleaded with him to dedicate a room to her (it will cost you €2,000 to get into bed here).

But it’s not all luvviedom: Treacy’s humble roots ensure the bedrooms are admirably down-to-earth too. So although they are as delightfully decadent and creamily luscious as a large Italian ice cream, they also raise the game of even mundane essentials: the laundry bag has an Anya Hindmarch-style print of his two Jack Russells, for example, and the bedside lamps look like sketches for his next millinery creation.

Contrast all that with another recent designer offering, the Hotel Puerta America in Madrid. It harnessed the talents of 15 leading designers and architects, including Sir Norman Foster and Zaha Hadid, by giving each a blank cheque and a floor or public space on which to work their magic.

Here, the emphasis is definitely diva, not duvet: it bristles with anything-goes outlandishness. I cannot imagine who would like Ron Arad’s black and blood-red creation — it has all the come-home-to appeal of a goth teenager’s bedroom. There’s no respite at mealtimes: breakfast juices are served in phials that look like NHS specimen bottles. It would take a braver guest than me to go for the apple juice.

Even when style is not at the expense of substance, high concept can falter when the label attempts to export its brand away from its home turf. Bulgari’s second property opens in Bali this spring — but how easily will its urban luxury style translate to an exotic Asian island? Perhaps that’s why one of the most successful crossovers is Lungarno Hotels, which has been going about its business rather impressively for 10 years.

Yes, it’s owned by a fashion house — in this case, the illustrious Ferragamo family — but you wouldn’t immediately know it: they’ve kept the two divisions as distinct (if complementary) strands. They’ve also never strayed from their Italian roots. The group’s six serenely delicious Florentine properties and its Tuscan idyll will be joined by the much-anticipated Suites in Via Condotti, in Rome, this year. I can’t imagine Lungarno ever migrating to Dubai.

OF COURSE, travel loves a gimmick, regardless of the guest’s preferences. Remember butlers? There was a time when no self-respecting five-star could open without promising that a Man Friday would be available to unpack for you. Surely most of us would rather eat a week’s worth of room-service leftovers than have a stranger handle our smalls? Likewise, who needs the bedroom to have a label, so long as what’s there meets the discerning traveller’s needs? But designer hotels can work. One-off projects such as Treacy’s Gaelic extravagance or

Christian Lacroix’s whimsical Hotel du Petit Moulin in Paris (all kitsch wallpapers, extraordinary collage frescoes and illustrations by the great man himself) work because they ooze the personal input of the famous name. It’s when that influence from the top gets diluted by the sheer number of openings that the concept starts to look more shaky. Can Armani really have time to agonise over the curtain ties at his 10th hotel? In the end, many of these designer hotels may prove to be rather like the designer outfits that spawned them: they’ll look fantastic in the photographs, but the average person might not always find them such a comfortable fit.

• Susan d’Arcy travelled to Galway with Aer Arann (00 353 1 844 7700, www.aerarann.com )
  
  
  
  DESIGN HOTEL DETAILS
  
  The g: 00 353 91 865200, www.theghotel.ie ; doubles from £325
  Bulgari Milan: 00 39 02 805 8051, www.bulgarihotels.com ; doubles from £340
  Hotel Puerta America: 00 34 917 445 400, www.hotelpuertamerica.com ; doubles from £110
  Lungarno Hotels: 00 39 055 2726 4000, www.lungarnohotels.it ; doubles from £160
  Hotel du Petit Moulin: 00 33 1 42 74 1010, www.paris-hotel-petitmoulin.com ; doubles from £180

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