Slic3r has this feature, you can specify a thickness for the first layer (i use 0.2) for better adhesion, which allows for sloppier and less frequent bed leveling. Unfortunately, after a week of using Slic3r I uncovered about a dozen bugs and every time I tried to post about them in the issue logger they seemed to be dismissed.
Either way, it's not a necessity but a nice convenience none the less.