Start with the daily itinerary
Official Seoul guides place Myeongdong with the central shopping and Namsan side of the city, while Hongdae sits in the west-side youth-culture and café cluster. If most days begin around palaces, City Hall, Myeongdong or Dongdaemun, the central base can reduce repeated cross-city travel. If evenings, cafés, Mapo and west-side neighbourhoods dominate, Hongdae keeps the end of the day closer to the room.
Airport access is not one headline
Hongik University is served by the AREX all-stop railway, which makes Hongdae a strong arrival candidate for a compatible hotel location. The reserved AREX Express continues to Seoul Station, so it is not automatically the best Hongdae train. Myeongdong normally needs a final leg from an airport rail station or a useful current bus stop. Compare the exact entrance, lift access and final walk with luggage.
Price and atmosphere belong to the live hotel
Neither area guarantees a quiet room, a low price or generous space. Street, building, floor, room type and cancellation terms matter more than the neighbourhood name. Use the area decision first, then compare live stays and map the shortlisted property to the subway exit and airport route before paying. A cheaper room that adds awkward transfers every day may not be the cheaper trip.