The westin is solid and the lounge is pretty good. Small, but usually never busting with people and ample seating along with very friendly staff. Great location and access to the BTS although I'd love for them to actually have a skybridge like the SGS!
Rooms are spacious and I used to get upgrades everytime although my last three stays I haven't???? Oh well nice property.
Having said this BKK is filled with great options and should be explored.