I am Diamond, There are actually 3 properties, Hilton, Embassy Suites and Doubletree. Doubletree is the cheapest and also has the cheapest parking. Views at Doubletree are not that great not much in terms of upgrade. Embassy suites is nice $20 CAD parking but views are spectacular.
Hilton Free breakfast as Diamond (was excellent) Parking $20 CAD and upgradede to a JR Suite with a good view of falls.
My preference Hilton.