The place itself is lovely: the rooms are clean and tidy, there's free internet, bathrooms are a bit small but they're continuously cleaned. the staff is incredibly nice. the kitchen is ok, a bit rustic but they were doing renovations when I left. It's really good value!
BUT the area is dreadful. and not really safe at night (as is most of Athens to be fair). This being said, a bit of common sense is all you need: I managed to spend 10 days there as a solo female traveller, with no problems: as long as you don't go around with a gold necklace or your camera hanging around your neck, you'll be fine !

I had booked a room for one night. I was coming with the ferry from the islans and would arrive in Athens very late at night (midnight) so I immediately informed the person, both via mail and via phone that I would be arriving that late. The same morning I called again, just to make sure that they would know and that they wouldn't think I wasn't showing up. They literally said "no problem, we know you're arriving very late!" Well, of course I arrive around 1 in the night and THERE IS NO ROOM.
I we want, they can put us in a sort of STORAGE ROOM for a cheaper price. It was night, I had no idea where to go, all the other hostels around were full booked and we had big luggage so we had to accept. The room was about 1,5 meter x 2 with a small bed, filled with old objects, dirty, disgusting bed linens, NO AIR, just a small window that you couldn't open, no toilet of course. We had to use a disgusting, dirty common toilet.
Don't go there, it's a total total rip off.

This hostel is cheap for a reason the only good things about it is it's close to Larrisa train station and the staff are friendly.
One of the guys in my room saw a cochroach escaping from the bathroom. Menwhile I thought the bathrooms smelt pungently of urine. The showers are located right next to the toilet and the hot water is minimal. There is no real communal area apart from the 2 computers in the entrance way or the small table next to the kitchen. The kitchen itself is dirty and consists of a microwave, sink and fridge with minimal utensils. The bedding is dirty so if you do get stuck here use your own!
To top things off the area wasn't the nicest so I wouldn't advice venturing out at night by yourself.

I was booked into a hostel around the corner but when i arrived conveniently they didn't have any beds so i was sent to San Remo Hostel. This place was an absolute dump. The staff were a bit strange, The bathroom had holes in the walls (big ones) and smelt of urine. I couldn't even stand having a shower it was that bad. The sheets on the bed were still wet and the room didn't have proper heating. There wasn't enough hot water for all of us in the room to shower. It may be cheap but pay a few extra euros and stay somewhere else.