Bear in mind that the glossiness value works a little differently since PBR mode was introduced - so depends on how old the tutorial is you are watching for Max :) That changed in 1.5, so any tutorials older than 4 months ago (when the PBR Shading in Corona tutorial came out) may show different settings or results.
In Max, darkening the Reflection Colour has the same effect as lowering the Reflection Amount - and with the PBR workflow, the general recommendation now is always to use a Reflection Amount of 1 anyway, and control reflections via Glossiness (Reflection Colour only being used for metals, and Fresnel being used to increase the overall reflection strength for metals). Again, the workflow is shown in the PBR Shading in Corona video, there's one for Max and there's a Preview version for C4D that follows the same points as the Max one:
PBR Shading for Max:
And the similar thing for C4D (a Preview, as there may be UI changes etc between this video and final release for C4D, so we'll likely re-record this as a final tutorial once 1.0 is out)
