that is correct, Link Pass does not work on ferry or commuter rail to zone 1A. So the 1A is the same price for more services.
the only down side of getting the 1A over the link pass is that the 1A charlie card needs to be replaced each month with a new card, but the link pass can use the same physical card each month.
the only down side of getting the 1A over the link pass is that the 1A charlie card needs to be replaced each month with a new card, but the link pass can use the same physical card each month.