Bangkok or Ho Chi Minh City?

Neither city is a place to swim, so in both you will be using hotel and rooftop pools. The difference is in the nearest escape. From Bangkok, Bang Saen and Pattaya are one and a half to two hours by road. From Saigon, Vung Tau takes about two hours, and you can go by fast boat down the river, but the water is often cloudy and the sand busy at weekends.

Either way, a proper beach stay means adding a separate leg: Hua Hin or the Thai islands from Bangkok, the central Vietnamese coast or the islands from Ho Chi Minh City.

Both cities are built around street eating, but Bangkok has more range at every level. It has Yaowarat Road's night kitchens, Or Tor Kor's produce halls, a strong tier of restaurants reworking regional Thai cooking, and a serious cocktail scene on top.

Saigon's southern cooking is sweeter and heavier on fresh herbs, with broken-rice plates, banh xeo and streets of shellfish stalls, and Cholon's Chinese-Vietnamese food is a cuisine of its own. Its coffee culture, from iced condensed-milk drip coffee to cafés hidden up old apartment stairwells, is where it can rival Bangkok.

Bangkok has far more to see. The gilded spires and mirrored tiles of the Grand Palace and Wat Phra Kaew, the Reclining Buddha at Wat Pho and the porcelain tiers of Wat Arun can fill several days, and smaller temples, Thonburi's canals and the Jim Thompson House add more.

Ho Chi Minh City's sights are about recent history. The War Remnants Museum and the Reunification Palace are powerful, and the colonial cathedral and post office around Dong Khoi are handsome, but the core takes two or three days. Cholon's incense-filled assembly halls are the main older layer.

Bangkok's nights out are bigger and more varied. You can choose between polished cocktail bars and clubs in Thonglor and Ekkamai, the cheap street party on Khao San Road, Silom's long-established gay scene and hotel rooftops high above the river.

Saigon's evenings begin with beer at pavement tables and peak on Bui Vien's loud neon walking street. Its best side is the speakeasy bars tucked up the stairwells of old apartment blocks near Nguyen Hue. Thao Dien has a quieter expatriate bar scene, and most places close in the small hours.

Both are flat, hot delta cities where nature means parks and trips out of town. In Bangkok, Lumphini Park has monitor lizards and Bang Krachao is good for cycling on raised paths, but real forest at Khao Yai or the river and limestone country around Kanchanaburi needs an overnight stay.

Saigon's green escapes are closer but stay low and watery: the Can Gio mangroves with their macaques and boardwalks, and the canals and paddies of the Mekong Delta seen by boat or bicycle. There are no mountains or waterfalls within reach.

Bangkok has the stronger choice of day trips. Ayutthaya's ruined temples and Buddha heads wrapped in tree roots fill a full day, best by bicycle. To the west are the Maeklong railway market, the Amphawa and Damnoen Saduak floating markets and the great stupa at Nakhon Pathom, with Kanchanaburi's Death Railway bridge as a long day out.

Saigon's best trips are the Cu Chi tunnels, often paired with Tay Ninh's pastel Cao Dai temple, and the delta towns of My Tho and Ben Tre. Beyond Vung Tau there is little else, and Can Tho's floating markets need a night away.

Children are made welcome in both cities, but Bangkok has more for them to do. Sea Life Ocean World, Safari World, Dream World and KidZania are all there, and the big mall play areas are useful on hot afternoons. The Skytrain and river boats are fun in themselves.

Saigon has fewer options: the old zoo and botanical garden, Dam Sen's rides and water park, and the eccentric Suoi Tien park. Its streets full of motorbikes make walking with small children harder work than in Bangkok.

Bangkok is easier to get around because of its rail lines. The air-conditioned BTS and MRT link the main districts and the airport, and express boats run along the Chao Phraya to the Grand Palace. The weak spots are the old city, which the rail lines barely reach, and the gridlocked roads between stations.

Saigon's centre around Dong Khoi is walkable, but its single metro line covers only one corridor. Most visitors get around by ride-hailing car or motorbike taxi. Crossing the road takes nerve, and phones are best kept away from the kerb because of snatch thefts from passing bikes.

Bangkok is one of Asia's great shopping cities. The Siam and Ratchaprasong malls are joined by Skytrain walkways, with everything from luxury floors to the bargain electronics of MBK. Chatuchak's weekend stalls of ceramics, vintage and crafts can fill a whole morning, and Thai silk and benjarong porcelain make good gifts.

Saigon is better for markets and crafts than for malls. Haggling at Ben Thanh, the wholesale stalls of Binh Tay, made-to-measure suits and ao dai in a few days, and lacquerware and Song Be ceramics are its strengths. Watch out for copies sold as genuine.

Both are very cheap by Western standards, but Ho Chi Minh City is cheaper still. Street meals, coffee and draught beer cost almost nothing, motorbike taxis are cheap and museum fees are low.

In Bangkok, money also goes a long way on food, massages and hotels with rooftop pools. The extra costs are the Grand Palace entry fee, heavily taxed imported drinks and the higher prices along Sukhumvit and the river.

Neither city is worth a trip for the stage alone, but Bangkok has more to offer. Khon masked drama is performed with lavish costumes at the Sala Chalermkrung and the National Theatre. Muay Thai nights at Rajadamnern and Lumpinee are worth seeing for the ritual and the music as well as the fights.

Saigon's colonial Opera House hosts ballet, the symphony and acrobatic shows about village life. Water puppetry and the sentimental songs of cai luong opera add local colour, though cai luong is hard to follow without Vietnamese.

Bangkok has the deeper massage tradition. Wat Pho still teaches traditional Thai massage in the temple grounds, cheap parlours on every street stay open late, and the grand riverside hotels run some of Asia's most refined spas.

Saigon's own ritual is the long reclining hair wash with scalp and face massage, and cheap foot massage easily becomes a daily habit. In both cities the noise and heat outside work against calm. For quiet, look to Lumphini Park in Bangkok and to temple courtyards or Thao Dien's slower streets in Saigon.