I used it on my first solo trip.
It's within a 10-minute walk from Jamsil Station, about 500-600 meters away.
Go straight out of Exit 6 (if you have heavy luggage, I recommend Exit 2, which has an escalator), turn left at the intersection with the Olympic-like object, and continue straight along the street.
(I arrived without getting lost even though I'm directionally challenged lol)
There were two men at the front desk during my stay, and both were very nice. They only spoke a little Japanese, but they tried their best to communicate with gestures and using a papago.
The room I was shown didn't have a bathtub, so I asked at the front desk.
It had been about 30 minutes since I checked in, so they were hesitant at first, but they eventually changed it for me.
It's better to tell them right away if it's different from what you booked!
(They upgraded it a lot, including the bathtub, so they may be quite casual about that. It was good that they changed it, but I don't think it's good to be the first to say it.)
I stayed alone in a two-person room for less than 10,000 yen on a weekday in late April. The bed was spacious (for one or two people), clean, and there was a window, so it was very nice.
Insect spray was also provided.
There were extra towels and other things in front of the front desk, so please feel free to use them if you needed them.
There was no information about the free Wi-Fi in the rooms, but I was able to use the one with my room number without a password.
There were also plenty of charging cords for smartphones.
A conversion plug is required to use the Japanese outlets, but this was included with the rental Wi-Fi, so it wasn't an inconvenience for me.
I was very satisfied with such a great price.
There are many expensive accommodations around Lotte World, so I highly recommend it!