PeakVisor developer (one of) here.
There are some people using it there for sure. We even improved some data from their feedback. Honestly, I think Canadian mountain names data should be mostly the same, yet PeakVisor has more detailed information (a.e. Wikipedia integration, topographical prominence / ultras, etc).
You can check data quality on the website. Open the Mountain Explorer there and search for any mountain, click on it and see what other mountains are visible from there. Here's a view from Mount Seymour
BTW, You might find PF vs PV comparison in the news section of the website.