Like Cartier, Tourneau, Tiffany, and others I think it is best to treat Horologio like a gallery - 99.5% of the time you're simply going in to look at the pretty things you cannot afford. That being said, every single time I've been in this store, whether suited in Armani or yesterday when I walked in with jeans and a T-shirt I have been treated with the utmost respect by the staff. While I hear a lot of people complain about customer service in Las Vegas I consistently find that these 'complaints' are related to tourists that would never be exposed to stores like this otherwise who wander in and are stunned that Franck Muller or Vacheron Constantin even exist, instantly assuming snobbery to be the case.
Let's face facts; there are rich people and there are poor people and there are those of us somewhere in between - Horologio as a shopping option is for the rich and the true 'enthusiasts' of the middle class. Go in with appropriate expectations and these folks will take care of you, even if that means just letting you try on that $46,000 Rolex.