I have had 2 Nikon Monarch scopes. Both came on slightly used rifles I had bought. Neither was earlier than 2007 vintage. I was disappointed in the quality of the optics. I was expecting much more based upon the MSRP and hyoe in the rags ... and based too upon the optical performance I have in a top of the Nikon bino that I have. I am not saying these were not decent scopes, just not up to what I expected.
My personal choice for a scope in the price range of a Nikon Monarch is the Zeiss Conquest. I have 2 and like them both a great deal.