I visited Jack's several times during my last visit and it is a great place! It's an instant favorite of mine in Boulder City.
The staff is friendly and nice, both at the bar and at the tables. The place itself is very nice and new, but with a vintage feel and vibe. Everything is clean and nice. The band they have there is great, they play country and rock type stuff, there are often a few people dancing as well.
The food is really good, and the draft beers are Texas pints, ice cold, and dirt cheap (especially coming from NYC). Stop by Jack's if you're in the area!