We have a nice sized vice unit with 20 some people working 40+ hours a week.  All of the girls that I know personally who have been arrested (including myself) have been arrested here in Vegas with the exception of 1 girl on tour in Chicago.  Stings on guys usually happen on the streets but I have heard of them doing it in casinos.

I am not really sure what your question is, but go with a well reviewed independent in Vegas and you will be fine.

I'll add some points on top of what Miss Logan provided.

Vice has a list of priorities:

1) underaged prostitutes
2) PIMPS
3) streetwalkers
4) solicitation inside gentlemen's clubs
5) any other prostitution/solicitation

They do setup sting operations to catch providers who advertise in the paper, flyers/brochures, Internet, etc.  And they do occasionally target guys.  It happens often enough that a little paranoia is a good thing.

A few thoughts:

1) You should not expect any privacy in Las Vegas.  The valley has a lot of surveillance (it's mainly related to gaming but a good deal of it is for security as well).  You will be caught on camera hundreds, if not thousands of times while you're here.  A good PI can manage to get enough circumstantial evidence against you if they wanted to.  If anything, the best you can hope for is discretion.

2) Vice is fairly busy because prostitution is illegal in Clark County.  If you're so worried about vice, your closest legal options are in Nye County where they have legal brothels that offer sex workers for hire.  The closest are in Pahrump, specifically the Chicken Ranch and Sheri's.
2a) Two things to keep in mind, it's a long drive to get to a legal brothel from the strip.  The drivers (both taxi and limo) get "toked" for taking you to brothel.  On the flip side, there's enough LE patrolling the roads that getting a DUI (or an accident) is a really bad idea, esp if you don't live here.

3) The pricing here in Vegas is some of the most expensive in the country, if it's not #1 (I'd say with a bullet but I think the pricing here has always been at or near the top of the charts).  If you have a chance, you might want to see someone closer to home so you have some measure of comparison.  There are some real gems out here in Vegas and they're worth their weight in platinum.

4) Having a VIP membership here is more than worth it when you compare the prices paid for a provider's time.  Knowing that a particular provider has a good track record here (via reviews and general word of mouth) will lead to a better overall experience.

good luck, have fun,
 Bob