I had a great stay at Best Louis Hamilton. The room was good and I slept well. There was a bit of dust and dirts in some corners around the bathroom sink, but not too much, so I wouldn't consider it unclean. The breakfast had nice options, good for the price, but if you want a really good breakfast, then maybe try the brunch restaurants of Busan, they are really good! The staff was nice and helpful!
In term of area, it was close to the Haeudae beach, which was awesome and close to a lot of restaurants (something like 10 min walk for good restaurants). However, Haeudae is quite far from the rest of Seoul, so make sure to plan it in your itinerary. There's no subway station close, so it's better to use the bus to get to the hotel.