I had a stay here last week, Tuesday-Thursday.

I was greeted as a Platinum Premier member, and was told that I received an upgrade to a larger room. The room was pretty large, facing Central Park, however it was not a suite. As a Plat, I was invited to enjoy breakfast in the restaurant, and evening snacks in the lounge.

The breakfast at the restaurant is excellent, with Chinese, Japanese, Indian, Western, and of course Korean offerings for breakfast.

Evening snacks in the lounge amounted to a light dinner. They had plenty of food, both hot and cold offerings, and both evenings had a different selection. The alcohol they offered was a step above some of the other hotels in Seoul, as they had a Glenlivet 12 in addition to the usual Jack Daniel's, Absolute, Jose Cuervo, etc. Surprisingly they did not have Ballantine's (which I saw at nearly all other hotels).

There is a small (relative to other Korean Sheraton's) fitness center. It has a couple of machines and free weights, but is nowhere near the size of the Plaza, Sheraton D Cube, or Sheraton Seoul Palace. They have a pool as well divided into lanes, and a small sauna with showers and two hot baths, and a cold bath.
I think access to the sauna is included for everyone, but not sure. The sauna (at least the men's sauna) can be accessed directly from the pool, so I'm not sure if it is included only for Plats, or if all guests have access to it.

The local area is pretty dry when compared to Seoul (which is just packed), but there are some bright spots. First is there is a convenience store directly attached to the hotel. So if you are hankering for a late night snack, you're covered and don't have to dress to leave. As Aventine mentioned, there is a Lotte Mart also nearby (corner of the same block), it's a short walk, and it's pretty sizable. It has groceries available, as well as electronics, toys, clothes, etc.
Across from the opposite corner, you'll see a bunch of restaurants and stuff (like Mad for Garlic, some lobster joint, there's a bunch).
Directly in front of the hotel is Central Park, and a small food court, which I didn't get a chance to visit, but it looks like they also rent out paddle boats for use on the lake.
Central Park has a number of paved walkways and bridges, and seems like a nice place to hang out during nice weather.

Moving further out from the hotel, a couple blocks away is a Costco, a large HomePlus shopping complex, and a large outlet mall shopping complex.

The hotel is also near an Incheon City Bus Tour stop, and is a stop for the KAL Limousine Bus to the airport.

I enjoyed my stay, and definitely plan on staying again, as I didn't get a chance to explore Incheon as much as I wanted.

If anyone has questions about the hotel, feel free to ask and I'll do my best to answer.