Rear blade or belly blade?

Hi my experience is that a belly blade does a better job of leveling and you can see the blade and whats happening easier. With the rear blade when the tracor wheel go over something higher the blade really moves do to the longer arm. Rear blade has its advantages as it can be rotated around and be used to get in close to a wall or corner etc.
I have a rear blade an am thinking of building a center one.

Both blades have their purpose, the rear blade for spreading material in quantity and the belly blade for levelling.

Rear blades are generally mounted on 3PH's that float. Great for spreading material as the blade can be adjusted with the top link to allow the material to pass under it at a set rate while following the ground contour. If the 3PH is made so that it can't float, the blade will follow the motion of the front and rear wheels. When the front wheel encounter a rise in ground contour, the blade will dig in, and when the front wheels encounter a dip, the blade will rise off the ground. The reverse holds for when the rear wheels meet the same conditions. The result is a worsening of the dips and rises of the surface.

A belly blade needs to have limited vertical motion when in use to be of any real purpose. As the front wheels rise, so goes the blade, filling in the low area just in front of the rise. As the front wheels go down into a dip, the blade will clip off the top of the rise and the rear wheels don't have as drastic an effect since the ground is closer to level for them.

Front end weighting is needed for a belly blade or steering can be a problem.

Small bites work better than large bites.

Likewise, a longer wheel base is better. See the reference above for guage wheels on a rear mounted blade. Although this method requires more manoeuvering space, it will result in a better job done a quite a bit faster. I built one as a tow behind unit many years ago. It worked alright, sorta. It needed more weight to do a good job.