From what I understand from short conversations with Vegas drivers, the Lyft base rate is slightly lower and the tips are significantly better. Your $5/nt turns into $1-2/ride. With tons of short rides up and down the Strip, it probably works out well.

There's gotta be a Lyft driver forum out there similar to your Uber one... I'm sure they have threads breaking down every angle of the comparison. Perhaps with different examples for different cities... Vegas seems like the ultimate short-ride place...maybe things work better for Uber in places where the airport run is a long ride.