I have stayed at Westin Grande Sukhumvit countless times. There are always newer, bigger, "better" hotels than Westin Grande Sukhumvit but I still doggedly chose Westin despite my suppliers saying "there are bigger hotels XX and YY" Perhaps ... I like her location; steps away from the BTS station ASOK, steps away from Terminal 21, a new and hip mall filled with choice restaurants, supermarket, pharmacy, steps away from Robinsons and Top Supermarket, steps away from a good value foot masseur, steps from amenities like hairdresser, manicure, and for the brave hearted...delicious "real" Thai food stalls along the road. I have stayed at countless hotels in Bangkok during my business and leisure trips and none have matched the convenience Westin can provide.
Perhaps its the staff? Westin also boost a good staff team who seem to stay, the people at the door, the concierge, the front desk ladies, the spa team, the breakfast team, it feels like coming back to somewhere homely and comfortable. Some seem to recognize me, for the reasons I hope. The lobby is comfortably scented and breakfast has enough choice for a week's stay. There are quite a lot of parking available beside the hotel. All taxis know where Westin is. And its not that far off from the airport about 40-60mins, traffic is always a little unforgiving in Bangkok.
The rooms are similar sized to that of a 5 star hotel in Bangkok, the club floors are a little larger, separate shower and tub facilities, good bath amenities and the comfortable Westin Heavenly bed, comfy room slippers and bathrobe.
There is only a little grouse: the shower mixer is a little old. Well that does need some fixing.
That aside, Westin is still my first choice in Bangkok.