We stayed at the Marriott Fallsview & it is very nice. My husband booked 2 suites, one for us & one for my mom & my aunt (who was visiting from France) as a Mother's Day present for all of us & we let our DS (then 6) stay with my mom in the adjoining suite.
As nice as it was, we had a very bad experience (but it wasn't the hotel's fault). At about 230am, the fire alarm went off. They are SO LOUD!!! We were all just kinda looking at one another, not knowing what to do. Suddenly, a voice came over an intercom & it said for everyone to evacuate the building, a fire has been detected. Once we got out into the hallway, we could smell smoke.
My DS
freaked out to put it mildly! We threw some clothes over our P.J.'s & I grabbed my purse, & my DS & we took off. I told my DH that I had to leave immediately since my DS was really hysterical. My wonderful DH stayed behind until my mom (age 76) & aunt (age 81) had some clothes on & then they evacuated too. Did I mention we were on the 21st floor? So that means since the stairwell is set up 10 steps, a landing & 10 more steps to go down ONE floor, we had to run down 42 flights of stairs!

Did I also mention I was 7 months pregnant at the time?
That D#@m'ed fire alarm which kept blarring & all the people rushing past us to get down the stairs as fast as possible, was really a nightmare. My DS pulling me down the stairs, I thought he would make me fall. Anyway, an angel came & she took my son by the hand & told my DS to let Mommie go down the steps carefully (as she could see my swollen belly). For some reason, he calmed down once she took his hand....(I truly believe she was an angel). Anway, we got down but I kept turning back & looking for my DH, DM & DA & they were not anywhere in sight. It was quite a while later that they finally came through those doors. Boy was I relieved! My DH did not leave them. Anyway, it turned out that the fire was in a room on the 22nd floor (above us) & the firemen were able to contain it but at the time when we were running down the stairwell, we didn't know where it was, or how big or if we'd even be able to finish descending. Tons of people in the lobby in their PJ's & hugging & crying. (My DS still jumps through the roof if he just hears a car alarm go off!) It was very scary.
We had to demand it, but the hotel did credit us that one night's stay & we checked out one day earlier than planned since I started having contractions!
The first night we were able to enjoy the view of the fireworks show, but be sure you are ready to see it at the exact time it starts, since it's only about 5 minutes long.
IF we should return (it's been nearly 2 years but still so fresh in my mind), I will not stay past the 2nd or 3rd floor (of any hotel!)
I know...I gave you too much information, didn't I? Sorry!

Hope you have a great time! The Falls are truly AWESOME!