I have been in many a cab and I can say the Vegas cab drivers are usually the most friendly of any as they know you are in town to drop some coin.NONE have ever taken the highway to get me to the strip area and I have never asked for a specific route. Some do drive like crazy though.
As for the cab line, I had about a 6 hour layover in Vegas on the way back home from the UT/USC game and I spent almost 1 hour of it waiting to catch a cab to get to the strip.
Turns out it was the weekend coming up for the Electronics show though.
If you are ever looking for a career change then becoming a Vegas cab driver sounds very lucritive. You are busy just about any time of the day no matter what time of year or how many cabs are on the street. Just pull up to a hotel and wait like 30 seconds max if there is not already cabs sitting there. It may be small money for a short ride but wherever their stop is equals another fare more than likely.