LEED is a nice concept for trying to reward "green" construction. Unfortunately, the more you look at it, the more it looks like a money-making scheme. All the fees are front loaded, rather than trying to actively support projects, there are fees at every turn, and ultimately, after the building is certified, there is rarely any follow up to ensure that the building maintains its intent. I think as the program evolves it will grow past some of the problems, but right now, it seems cheap.
As for benefit, I am a water/wastewater engineer. There is a little benefit when the company goes after projects, but not much on the day to day. Traffic engineer would probably see the same thing. Mostly, accreditation is great for plumbing, electrical, HVAC, and civils.