In A Nutshell:
-The Club at LAS in Terminal 3 is a nice lounge.
-It's much, much bigger than The Club at LAS in Terminal 1.
-The bar is very nice and fully stocked.
-The food options consist of snacks, fresh veggies, mini pizzas and sandwiches.
-If you needed to freshen up after partying hard in Vegas, this lounge has a mediocre shower (better than nothing).
-The lounge has plenty of seating and plugs to recharge your mind, body & phone.
Overall, if you had to choose between Priority Pass lounges always go with Terminal 3 over Terminal 1.