No rentals in this area that I have come across. That would be a huge benefit.
I would say the thing it does the most is cut root-bound clumps apart and allows clump grasses to spread. Also more water gets down to roots and improves drainage.On an old hayfield what do you notice different the next year? Better drainage, yield, or both assuming aerating is the only thing you did to the field
I core aerate my 5 acres at least once, if not twice a year. Really helps with compaction, and getting nutrients down to the roots of the grass. Have a fair amount of clay, so compaction is a problem.
If I overseed with rye, then I have to mow it 2-3 times in winter. Not crazy about that, but to each his own.
I would be going out beyond 100 miles. Local dealer a no go.We have a couple different companies that rent spreaders & aerators.
Have you tried local dealers who sell them?