Was there in November, and I was impressed. Surprisingly, the restaurant food in the evening was better than breakfast, which was just OK (and free for Diamond, of course).

Did get upgraded both times - not a major upgrade, and King to King Deluxe, then the next week from King Deluxe to King Premium. My rooms were fresh, clean, quiet, and reasonably spacious. 25% discount in the restaurant, plus a free drink, meant that the food was excellent value.

It is definitely a lower end hotel by brand standards in Thailand, comparable with the other DoubleTree further along Sukhumvit Road, and usually a little cheaper. The location was beautifully quiet, more so than the other DT on Soi 26 - although the prices are getting up there. Below 3k THB it's good value, but lately, prices seem to be well above that, and while all Hiltons are quite strongly priced at the moment, this seems to have gone up in price a lot and is dangerously close to some of the other, nicer properties, never mind non-Hilton options.