I enjoyed the Marriott Sukhumvit generally - though, the Marriott Marquis the evening prior set the bar a bit too high for comparison. Regardless, I can tell this is generally a good property. Here are my pros, cons, and photos:

Pros:

• Upgraded to an "Executive" room - I looked online, and the only suite type showed "1 room left" - I'm a bit unsure on the room layouts here as the building is oddly-shaped, so I can't really comment on if my room was more impressive than others would be (I have a hunch that my room might have been a bit smaller than others)
• Bed was decent - the mattress was probably close to needing replacement (firm), but pillows were plush and covers were decent considering the needs for the tropical climate
• Shower pressure was strong from the rainfall head
• Light woods throughout were nice - including the flooring
• Service was quite friendly - interesting reception with 3 employees greeting me after being escorted to the lounge
• Offered 4 PM late checkout proactively
• Lounge offering was nice - tasty iced latte upon arrival, nice lounge desserts (I didn't try the appetizers as I had already eaten)
• Given a nice box of nine chocolate truffles with various fillings
• Offered restaurant breakfast - really tasty pancake station, nice eggs benedict, tasty hashbrowns

Cons:

• View was directly facing the nearby apartment building - any other side would have been better
• Shower wand column was loose and the wand seemed to automatically tilt out towards the door (and, consequently, you)
• No Internet streaming options on the TV
• WiFi disconnected upon every lock of my iOS device (not an issue at other hotels but also not an issue with other devices

Overall, I would consider returning - though, I would likely pick the Marriott Marquis between the two.

Photos: