I attended Mass while in Vegas on business.  The deacon asks visitors to stand before Mass and introduces / welcomes you to the church community.  I thought this was very thoughtful.  There are no kneelers so you stand when you would normally kneel.  The altar is in the middle of the room with everyone facing in which was nice.  There was no crucifix so I know that would have bothered my wife had she been with me but all in all I really enjoyed Mass.  Felt very inviting and comfortable.