Screenshots of Courier New vs. Liberation Mono rendering:

Examples are in the following order:

1. Courier New, grayscale AA
2. Courier New, emboldened, grayscale AA. Config snippet:

   <match target="font">
     <test name="family"><string>Courier New</string></test>
     <test name="pixelsize" compare="less"><double>36</double></test>
     <test name="weight" compare="less"><double>100</double></test>
     <edit name="embolden" mode="assign">
       <bool>true</bool>
     </edit>
     <edit name="matrix" mode="assign">
       <times>
         <name>matrix</name>
         <matrix>
           <double>.92</double><double>0</double>
           <double>0</double><double>1</double>
         </matrix>
       </times>
     </edit>
   </match>
   

   Note: Some pixelsizes look better with an additional edit like this, to remove artifacts caused by the hinter (in particluar, 12px):

   <edit name="hinting" mode="assign"><bool>false</bool></edit>
   

3. Liberation Mono, grayscale AA