More seating please!
Ok on the plus side there are a lot of food and shopping options inside the Las Vegas airport. You can find something to eat and drink and they even have oxygen bars.
My issue though is the overall layout is a little too crammed and there needs to be more seating. The slot machines are awesome, but they take up a lot of space. During busy times all of the regular seating gets taken up and you can't sit in any of the tons of empty slot machine seats unless you're playing one.
I encourage you to take a look at a map and the signs if you are catching a connecting flight. When I flew through last week I started running to catch my next flight at a gate that was a much higher number than the one I came in on. Little did I know the other gate was just around the corner from where I was at due to the funky layout.
On the transportation front I forewarn that the taxi line can get really long and the rental car center is pretty far off site. I personally lean towards booking a car service. It's a little more pricey but it makes the Las Vegas airport ground transportation a little more bearable.