The rooms on the main side were nice (we did pay for the upgrade). We had two beds that were clean and fresh. There was a nice big window with a view of the sea and cable TV. The room had a strong air-conditioning, but it had some quirks. There was a fully stocked bar with snacks to buy, and most importantly, bottled water.
My main complaint was the attitude and friendliness of the place. No one went out of their way to be nice, and you often had to ask a lot for things. We called for a ride from the airport, but the shuttle "was not working," (In reality, a taxi cost $20 versus $10 per person for the shuttle.) We arrived planning to book the next day's trips, but the tour desk was randomly closed for the entire day. The pool on our side was closed (no one told us), and on the other side, it looked kinda dirty and extremely deserted. The dinner menus in our room were never correct, food was generally just mediocre, and phone charges were pure robbery.
The overall mood there was deserted! It was almost like a ghost town; we later learned that we were there on non-cruise ship days. HOWEVER, considering other options in Belize City, it might have been the best. Princess Casino looked big and decent, but was in an area all by itself, whereas Radisson was close to the tourist shops and other restaurants.