This was a really great hotel for what we needed it for. We were here for the Green Day concert at the TUI Arena and it really is right next to it. The staff were very friendly and helpful and spoke fluent English. The buffet breakfast was the best breakfast I've ever eaten at a hotel and was really good value. The restaurant otherwise was a bit expensive but it was very nice. The rooms were clean and we slept well. Very quiet, never heard any noise.
However it really is in the middle of nowhere. It's a 50 euro taxi ride each way to and from the airport and apparently the train station is two miles from the hotel, and there ISN'T an airport shuttle like most websites tell you there is (although that's not the hotel's fault). The only shop nearby is a little convinence store called Petit Bistro which is very nice and has quite a good selection, but there's no proper restaurants or attractions or anything.
But if you're here for the TUI Arena or the Expo Plaza, definitely stay at this hotel. Apart from the location it's perfect.

Nice staff, great breakfest, expansive food. Perfect loction for "Messe" visitors.

I was at the Radisson Hannover in August.
It is on the Expo Plaza, practically on the highway.
It is a modern hotel built for the Expo 2000.

There is a large covered parking (2 storey).
I had a room on the highway side; the windows were sufficiently soundproof but not perfect,as almost all the windows that can be opened become after a few years.

Sufficiently large room, fine bathroom, all the usual amenities for a four star hotel.
Trouser press, great selection of international TV channels.
Unfortunately the TV is an old looking CRT model (approx 20") and the interactive services are not of much use.

Free Wired and wireless internet.

I had room service; there was a good pizza and a sufficiently varied menu.
Breakfast in the restaurant was OK; very little glasses for juice; little selection of pastries; yoghurt only in large bowl.
I think that all hotels should provide commercially packaged yoghurts.

It's a good "4 star standard" hotel, with all the expected services, comfortable, easy to reach, with easy parking and fast connection to the highways and the town centre (approx 10km), if you have a car.
There also is an Aral service station just a few meters from the Hotel (on the front/highway side), where you can also easily buy the usual things in the always open shop.

This has to be one of the best hotels I've ever stayed in. I stayed there for three nights and it was a great experience. We were there to attend a fair, which was right next door! The hotel is quite a way from the airport but there is a train station nearby and you can reach city centre in 15 minutes paying only 2 euros. The rooms were modern, well decorated and clean. There were tea and coffe making facilities and the wireless free internet was also a plus. The bathroom was large and spotless. The restaurant was o.k., though quite expensive and they made a few mistakes on what we ordered. The waitress keeped asking us if everything was o.k. and if we were enjoying our dinner, which was a little bit annoying, because this happened many- many times. Breakfast buffet was very nice with a huge variety of cold and hot dishes. In general, the personnel were very helpful and polite. I would certainly stay there again.