We use Trimble.
All of the civil engineers we use have it, so we're all on the same page. We use the GPS system to set foundation corners, mark utility locations, and control the AccuGrade system. We have the laser for making sure grades and slopes are correct to the plans.
At the end, we have a complete set of as-builts for each project for the future stored in the project file.
I have said it before and I will say it again: the Trimble rep drives a much nicer truck than I do, and the Trimble trainer drives a nicer truck than the both of us.
If you get plans from engineers frequently, ask what they used and buy the same system they use.