KalebOutWest -- I agree there are many Catholics in LV and an incredible Catholic high school. I know all about the Mormans here. At one time more Morman wards in LV than anywhere other than Salt Lake. Many professionals - Morman dentists/doctors/lawyers but it's changed much the past 20 yrs. All the teachers many moons ago were Mormans - all changed today which is a good thing. LV has a Morman temple.
The LV Guardian Angel Cathedral is definitely beautiful. Have attended many weddings there. Catholic tourists (high rollers, celebs) visit/attend mass and contribute generously!! They're doing something right.
There's nothing beautiful or outstanding about the JW halls here. I know where a couple are and that's enough - I like the new modern, style, of the recently constructed one but clearly doesn't look like a place of worship. Looks out of place in the area it's built - actually, more upscale property (compared to others) for a hall. Property was most likely donated. Some halls might be full with the influx of new residents to LV -- I'll try to find out. An older hall on east side of LV has only elderly w/one teenager and I don't think it's more than 60-70 people but I'll try to confirm.