I did the walk down the hill once and got lost; it's perfectly safe, but a bit annoying. I never walked UP the hill, I always took a taxi (they are cheap at W1600 for that ride, about USD1.25, no tipping). It's about 1km from Itaewon subway station, and it's steep, you'll notice it if you walk uphill.
As I noted earlier, rooms are quite small and if you want a larger room, reserve and pay extra for the corner king.
There is a concierge desk on the ground floor but I think they mostly staff it with people from behind the desk. They were unable to answer any question I posed to them, even simple ones like "where do those bus lines that run next to the hotel go to?"
If you're not on the club floor, bring food or a lot of money. The restaurants are a popular destination for Seoul residents, so they probably are doing something right by making them exclusive and expensive. It's just rather scary if you are staying here.