I stayed five nights in a very affordable double deluxe room at the WD Hotel. All of the staff were kind and helpful whenever I had any questions or issues (my card to the room didn’t work at first but this issue was quickly resolved).
Breakfast consisted of fruits, soup, kimchi, rice, fried eggs, cereal and bread among other things. Although the cuisine primarily consisted of domestic foods I felt that is was more than sufficient.
As for the room itself, it was quite spacious with a big bed and a large bathroom with all the toiletries you could wish for. Each room has its own Wif-Fi access point so internet access worked great throughout my stay.
WD Hotel is located in Sillim which is quite far from most tourist attractions, it is mainly a residential area. It is however located close to the subway (about two minutes walk from Sillim Station, exit 6) which quickly gets you around Seoul. As far as I could tell I was the only European staying there but this was never an issue as the staff could communicate in English.