I would always keep my old topped up to max, and also change it every 3 months, not that i have noticed using any oil. Good regular oil changes and respect for what your engine uses it for is an easy way to increase engine life.
When cornering the oil in the sump is under the same forces as you are in your seat. Bearing this in mind and the position and length of the pick up pipe in the crank case, you can imagine that on occasion the pump may starve of oil, causing damage, despite the baffles.
As already noted more oil means the overall oil temp will be lower than the same engine with less oil.
Do yourselves a favour and keep it clean!! especially if you give it some stick, if not then remember the italian tune up!