I have been to Seoul 3 times for the past few years and only stayed at Classic 500.
Though a little pricey, the room is absolutely worth it. We always get the suite for 3 ( we have 2 adults and 3 kids) and it is like a home away from home for us.
Basically, once you enter, there is a huge hallway for you to place all your jackets. Then it leads to a huge living room plus a working table.
There is a small kitchen complete with induction stove and pots/cutlery to cook breakfast and a very handy microwave oven. ( And a fridge as well)
You would also find a washing machine and dryer. A must have for long trips away from home.
The bedroom has tons of cupboards and two double beds joined together. There is even a vanity counter for makeup.
Bathroom is well equipped with standing rain shower and Japanese style bidet. There is no bathtub (it being built as a high class residence for the elderly - the other side of the Residence)
Our family loves the location as it is just next to a Lotte Mart and shopping complex called Starcity with cinemas, shops , restaurants, e-mart(try to go there to get all the Korean foodstuff etc). The insta worthy Common Ground is just a mere 10 min walk away. Plus all around the residence are small restaurants (from traditional ones to fusion), shops and coffeehouses.
And the subway is just 5 - 10 min walk from the residences, else take a cab cos it takes like 15 min to Jamsil or 20 min to Myeongdong. Cabs are not too expensive when you have 5 or 4 in a group.
The doorman/concierge are always so polite and helpful. Always willing to go the extra mile. And they speak wonderful English too!
We are looking forward to going back Classic 500!