We booked one night to treat ourselfes during a road trip.
For an extra fee, we got a very tidy and large room with fall view and whirlpool (behind a large glass wall).
There was a nice looking desk and a big flat screen.
Car parking in the basement.
Starbucks at the lobby, as there was no breakfast included, we decided to go the cheaper way :-)
Nothing bad to say against this hotel!

We had a room on the 19th floor with a great view of the falls. For what they charged me though, I would have expected a much more nicely appointed room. They were standard hotel accommodations; if I closed the drapes I would have thought I was in a Days Inn somewhere in Nebraska. And the fireplace, which I paid an extra $90 for, was a not just a fake fireplace (which I, naturally expected), but a fake fake-fireplace - some sort of electric beast that didn't warm up, didn't have flames, and made an ungodly noise...kind of like a giant cold toaster oven. I don't know what other hotels there are in Niagara Falls (which, after spending time in the beautiful cities of Montreal and Toronto, underwhelmed me as a dumpy and unimpressive tourist trap), but don't spend too much money to stay here.

Recently took a trip to Niagara falls and decided to stay here based on reviews and friends' experiences. Was a great decision! Absolutely beautiful view from our room, fantastic staff who were very friendly, helpful and accommodating. Ate dinner and breakfast at the Terapin Grill and enjoyed the view of the falls while we ate. No complaints at all. Absolutely would stay here again.

My wife purchased a package for us as a Christmas gift. I called in advance, and attended at this hotel, with brochure in hand. To my surprise, we were directed to another Marriot property (Gateway) which is almost across the road. We attended at the Gateway, and they could not locate our reservation. Ultimately, they found it at the Marriot Fallsview, where we were to begin with. We returned to be greeted by Lawrence, the Duty Manager. He resolved all of the confusion by providing all of the amenities (coupons for a Casino credit, $40.00 for the Terapin Restaurant, coupons for the buffet breakfast) we should have had.
I believe what occured is that the package purchased by my wife was for the Marriot Gateway, but I inadvertantly booked at the Marriot Fallsview. We have a spectacular room overlooking the falls, a wonderful dinner and buffet breakfast, and found the entire experience (after the initial confusion) to be wonderful.