1. The location: On the hotel description it is nowhere mentioned (obviously), but this place is located directly in the middle of one of the bigger prostitution streets in Bangkok. If you visit Bangkok for the very first time, you should be definitely aware of that, because it will bring you some very disgusting experiences.
2. The place is nearly not accessible with the taxi - You always have to walk into a small street, because it is very small and mostly blocked by prostitutes (no joke).
3. The smell: When you visit Bangkok, you should be already aware of the worse smell you can discover there. This hostel, on the other hand, pushes this smell to another level. The whole ground floor smells like someone died there weeks ago and would still wait for his check-in on one of the (never cleaned) chairs. The reason is that nearly the whole personal sleeps within the lobby.
4. A partially working wifi. If you have an iPhone, you will have a lot of fun with the wifi there, since it only lets you connect within the lobby and not with any other of the networks. Depending on the room, you may don't even get a signal from the lobby.
5. Language problem: None of the really understands English. I tried very hard, but there is no chance of good communication.
6. Unfriendly personal: When we had problems, they were advising us to fix the stuff by ourselves rather than doing it for us. They also laughed about our problems and were not interested in helping us.
7. Stolen items: On our second last day, someone removed my GoPro from the Apartment. When I mentioned it at the reception, they said they haven't seen anything and laughed again about our problem. They also use towels taken from hospitals.
8. Black Marketing: Inside the reception is a sign that says the following: "Rate us with five stars on Tripadvisor and get a free drink!" - That speaks for itself.
I discovered a lot more issues with this hostel, but booking.com limits the amount I'm allowed to write here.