The Arena is a clean, seemingly newly renovated hotel very near the convention center. It was easy to get everywhere from here. The staff was nice, and it served its purpose (I was in town for the book fair). If you are going to just sleep in the room and be out all day, maybe running back to change before the evening, then this is fine with good food options nearby; Leipziger Strasse had places to eat, a grocery, etc. The down sides is that room I was in was VERY small (and I live in Manhattan, so I know small). I literally had clothes hanging everywhere for a week's stay. It was clean -- yes -- but a single is truly a single; I could not take more than two or three steps -- if that -- without running into a wall, and had a single bed. Also, I was on the back side of the hotel, but I can imagine that the front side would be noisy with the trains. Also, they did not replace dirty drinking glasses each day, which after having a bit of red wine the night before was gross, and I think I used the same towel every day. I do that anyway, but it was not my choice, it was just how it was. In short, if you are not going to use the room for anything but crashing at the end of a long day, maybe watching a bit of TV (Netflix or other on your computer if you don't speak German, of course, b/c all TV is dubbed) then fine. Otherwise, if you want to have a room you look forward to returning to at night, with business-friendly amenities, look elsewhere.