I was going to give it three stars, but the experience with and assistance from the staff at WeHost turned out excellent at the end, and so I "upgraded" it to four.
On the plus side: Good location for public transportation (though see the point below about the neighborhood) ; the essentials were there, and in good working order; inside, it was relatively clean; and yes, the sofa bed was as comfortable as a normal bed; good "cocoon" place for a short stay, better if single, a little too snug for two. Staff very patient and cooperative - the We-Host office staff helped me a lot at checkout - even re-arranging a taxi call for me.
On the minus side: not much space to store your stuff (I recommend travel lightly); the street can be very quiet....except when it's not: the apt is on the 1st floor, which is not ground floor, but comes pretty close, and makes it feel like the people walking on the street below are literally in your house. Traffic, too, can get very loud during the day. The time between midnight and 7 am is quiet though.
The neighborhood is OK, except the very street on which sits the apartment and two or three other adjacent streets . On our first outing, my girlfriend was solicited and harassed by a drunken ...how do I put this correctly?... "street fellow" - we soon learned to avoid that corner. Unavoidable instead was the stench that came from the stairwell - a mix of roadkill smell and burnt cooking (we later saw the interior of our next door neighbor, as his door was ajar, and confirmed it was a stinky mess, yes).
So in conclusion, I traveled here for research, and I do recommend the place, but mostly for single travelers on short academic stays (I would not come back with my partner - the place doesn't spark "romance") - or perhaps for young couples on a budget string.