Yes, Andreas is right. You can add as much computers as you want in a LAN to one single Lightwave license to render images for a video. This saves a lot of money if you often render animations.

Besides that I found a website with benchmarks of 3d app rendering times. And Lightwave renders indeed a bit faster than Max, Maya or other tools mentioned and is much faster than Mental Ray.
Also interesting is: Lightwave gets faster with every core / cpu, and if you have 2 cores instead of 1 then it indeed doubles the speed (half of the render time). A quad core cpu or several cpus bring a lot for rendering images in LW.