Park Hyatt Seoul
Booked: a Park King for 20,000 GP points
Received: "Park Executce Suite" on 22th floor with great Gangnam city view.
Didn't use a DSU for this suite but it's my first time in this particular layout suite.
I'd save your DSU for a more special property. There's nothing wrong with this suite. Spacious but just a bit bland and reminds me of when the hotel was built in the mid 2000s. Not a whole lot has changed since then.