I stayed at tulip Inn on a business trip for 3 weeks and after that I had several similar assignments in Mannheim which I stayed in other hotels but I can say that I was never as comfortable as I was in tulip Inn, first of all the kitchenette is awesome if you are planning a long stay and don't have time or energy to go out for dinner every night or you want to make your self some snack.
all of mannheim tram lines also pass from a 5-10 minutes walk from the hotel in paradeplatz and you can find a PLUS supermarket near the hotel for food shopping and the mannheim shopping center within 10-15 min walking.
The breakfast is also very nice specially better than my experience in Italy!
I will ask the company to book tulip inn for me for my next trip!

I stayed at the Tulip Inn after a week of traveling through Europe with a group of 150 people. The lobby is so small that the only option is to line your group up on the pavement outside. This is also not the most desirable area of the city from what I understand. My room was on the 5th floor. Don't be surprised not to see the number 5 on the elevator. It is level D, so go on up. The elevator is larger and quicker than most of the others I encountered in Europe. The rooms were small, but the kitchenette was a great touch if you plan to stay longer than the one night of my stay. I also thought there was free high speed internet available. WRONG. Something like 20 Euro to get 24 hours worth of service. The bathrooms were small, the rooms were a bit warm and small, but the bed was clean and comfortable and after a few beers at the downstairs pub, I was sleeping like a baby. I am sure there are nicer places to stay, but you won't hate this place if you have to stay here. Also, the breakfast they offered was the best that I encountered throughout my journey.