While I haven't stayed in the hotel, I just looked it up in Google
http://www.hotelturin.com/eng/
The Raval district is really sleazy, but the hotel is only a block or so off Las Ramblas so it should be OK. It does look like a nice property so I would go for it. It is in a great location to see Barcelona's major attractions.
Just make sure you head towards Las Ramblas and not away from it...VBG. On the other hand, do explore the Raval district for some insight into Barcelona's darker side.
Tom