Well, the video poker there is lousy...and when the VP is lousy, the slots are usually lousy too. I've never been to the Niagara Falls casino, but I've heard some surprisingly negative things about it. My gambling experiences in Canada have been in Vancouver and in Calgary during the Stampede. I wasn't impressed. HOWEVER, I did manage to clean up at poker.
I kind of feel that I never want to gamble when I'm anyplace attractive or interesting. That's why Vegas was so suitable to me for so many years--it's an ugly wasteland with no culture and a huge gang of greedy, addicted people. Nothing to do but gamble. So I can't really imagine myself going to a beautiful place like Niagara Falls to gamble (eh?). Likewise, I could never imagine going to Tahoe and wasting my time there gambling. Or New Orleans, or NYC...etc. But a casino on the Hooka Pooka reservation 85 miles from the nearest settlement...that works, too.
I did have an interesting mini-AP play going for a while about 20 years ago. The Comstock in Reno would exchange Canadian currency at $1 CDN = 90 cents US. The thing was, the exchange rate was only .75. So when I lived in Seattle, I would go to Vancouver and buy $4,000 CDN, which would cost me roughly $3,000 US, then fly to Reno and cash that $4,000 CDN at the Comstock for $3,600 in chips. Free weekend in Reno! I did that four times.
You might ask around some of the casinos on the US side of the border to see if they offer a bonus exchange rate. Of course, they might want Canadian ID. For whatever reason, the Comstock never did!