In much of its coverage area, WRZN competes for the 50-plus audience with WVLG, 640, a station based out of the Villages, owned by its development company.
Comparing the two, WVLG seems to have local personalities and is always talking about local events. The station had insurance adjusters and similar folks on in the days after the 2007 tornadoes (although saying "It's a Great Day in the Villages" after a tornado had torn through the area and killed several people was a bit much). Its music mix seems better targeted at the leading-edge of the current generation of seniors than WRZN's satellite feed, which seems to be stuck in a 1990 vision of what the format should be.
I don't know whether WVLG accepts advertising outside the developer's facilities, but if it did, it would seem to me the stronger choice of the two for the target demo. I'm sure WRZN gets higher numbers most of the time since the Villages is technically outside the Ocala-Gainesville market.