Grand Hyatt Seoul -- Good hotel in a terrible location
I'm writing this from Seoul. As a Diamond, I was upgraded to the club floor, where there is breakfast service and a "happy hour" with some food. That's good, because the hotel restaurants (including the take-out "deli") are breathtakingly expensive, and there isn't much in the way of alternatives nearby.
The hotel sits up on top of a steep hill, and the nearest subway station is at the bottom. It's a nontrivial walk, especially uphill, and you can get lost.
The hotel runs a half-hourly shuttle, starting too late at 10am, which runs on a long and strange loop. Insead, it should merely go to and from the bottom of the hill and run much more frequently. Fortunately, taxis are cheap (if you pick the right kind of taxi).
How about a guide to using the frequent city busses that go nearby?
Rooms are quite small, but there a few "corner king" rooms which are $20-25/night more and materially better. My suite upgrade, using the Diamond upgrade coupon, didn't materialize. They lost the request made through reservations, so I didn't see any suites -- I traded them the coupon for the corner king room.
Since Hyatt can't move the hotel, I sadly conclude that absent better connections to the rest of town, I would probably stay somewhere in a better location next time.