I've stayed there probably a 15 or 20 times since opening, and also at the Kingsley once.
I'll start with the Kingsley. It's a total dump. They do upgrade plats to big corner suites, but it's still a dump. Not much to comment beyond that. I stayed once, and will not be going back.
The Westin isn't perfect, but I really like it and on the balance, it's one of my favorite hotels to go back to (will be there in a couple weeks, actually). Truly feels like a home away from home for me.
Pros:
- Standard rooms are very new, well sized, great bathrooms, great views.
- Staff is extremely friendly, attentive, and really have gone the extra mile for me on many occasions. Sometimes small communications/language issues.
- Exec lounge is nice, rarely crowded (more crowded on the weekends actually).
- Breakfast buffet is excellent.
- Gym and pool are very spacious and top quality (though a bit of a trek to get to)
- Air conditioning in rooms is super cold! How I like it.
- Platinum Suite upgrades are rare, but the suites are very nice when you get them.
- 3 blocks to Lake Xuanwu, a really great urban park. Nice place to run in the mornings, or just people watch any time (but particularly around dawn with Tai Chi, dancing, etc).
- 2 blocks to subway, which is 2 stops from the Shanghai high speed train. Much easier than standing in the endless cab line at the station!
Cons:
- Room service choices are a little limited
- Non-smoking rooms *occasionally* seem to be smoked in
- Not a ton of restaurant options in close vicinity. The half-empty luxury mall it is build next to has a couple not-so-great options... The hotel restaurant is fine.. but Hunan Lu is about 2km away and has a lot more choices. Just a 10 minute walk or so.
- Elevators. Lobby on 23rd floor, gym and conference facilities on 9th floor, rooms 24-35 floors. Only 3 elevators means there's some waiting, and crowded elevators at times. Annoying soundtrack in the elevators.
- Internet is not great (nothing different than most Chinese hotels)
If you have any specific questions, I should be able to answer. Really no comparison between these two properties.