I traveled here a few weeks ago (Jan 2013) and thoroughly enjoyed my experience. The hotel is in a great location; with a direct view overlooking the falls, it’s only a few minutes drive from the “strip” (which has many family friendly activities and restaurants) and about a half hour easy drive from the wineries and wine village. There is a restaurant (which I highly recommend) that overlooks the falls and fireworks display. I suggest making a reservation either the night before or early in the day if you plan on going to the restaurant. The hotel staff was very accommodating, and I received a free room upgrade upon my arrival. The rooms are spacious, clean, well lit, and mine had a perfect view of the falls. There is also small fitness center with free weights and treadmills, a pool, and a spa all within the hotel. This hotel doesn’t have a casino, but it is only a 5 minute walk from one. Although you will pay a little more than some of the other hotels on the block, it is well worth it.

Great views, stayed on the 28th floor overlooking the falls. Service was a little slow and internet wasn't working well. Elevators were SO SLOW! This was probably the reason I may not return. Of course, the drinks were over priced in the bar as well. Spent $8 for a beer when it was $4 around the corner.

We travelled in early February 2013 on a Groupon deal, which included a $75 off coupon to the Terrapin Grille, buffet breakfast for two, Jackson Triggs wine tasting at the Terrapin's bar before dinner (5-7 p.m.), wine tasting/tour at Jackson Triggs and Inniskillin wineries (you have to drive to those), and a two-day Wego bus pass, all for $129 Cdn. (We paid $20 extra to go on a weekend on this Groupon.) A fabulous deal and wonderful stay! The food at the Terrapin was excellent, both at dinner and breakfast. (Loved the made to order omellete/egg station for breakfast.) They take reservations, but it's first-come first-served at the window seats, so they advise going before 6 p.m. for dinner if you want to be by the window (view of the falls). The service was excellent at both dinner and breakfast!
The room was very comfortable, tastefully decorated, quiet and immaculately cleaned. The bed was very comfortable.The bar fridge is locked, so we didn't bother to get a key. Used the ice bucket to keep our drinks cold.
They have two hot tubs, a pool, steam room and sauna, gym and spa.
There is no on-site parking, and one has to pay $25 to either walk 2 blocks to park, or have valet parking. Having walked the two blocks, we definitely recommend, for the same price, to do the valet parking. We just stayed one night, so am not sure whether it is $25 per night or for the stay.
There are two Marriott's: one in front of the other, so make sure you know which one you are staying at, just to avoid any check-in confusion.
We definitely will be returning!

From the moment I arrived, the staff were welcoming, informative and professional. Great room with a wonderful view. I was travelling alone and dined at Terrapin on my own. I couldn't have felt more welcomed. Todd and Susanna, two of the staff there were marvelous, professional, charming, attentive. Dinner and breakfast both great. I was pleasantly surprised by the quality of my dinner meal. Lots of variety and healthy choices available at the breakfast buffet
Pool area good, with two hot tubs and dry and wet sauna.
I would recommend this hotel and will return.