I purchased my first VX5HD 3x-15x-44 scope earlier this year. Liked it so well I wound up purchasing three more with varying reticles. (I already have 7 Vortex optics and like them as well).
Glass quality is excellent. 171930 with the 56mm objective gives fantastic light transmission, and allows me to see license plates after dark down the street and read the plate better than any other scope I own except the Vortex PST Gen 2 5x-25x-50mm FFP scope set to 15x (to match the Leupold), which was the equal of the Leupold VX5HD 3x-15x-56 in allowing me to read a license plate.
My biggest reason I chose the Leupold scopes over another scope of similar specs is weight. I also got to compare a Vortex 3x-15x-44mm PST Gen2 scope to the Leupold version. Glass quality to my eyes was tipped in favor of the Leupold.
I've looked at some VX3HD scopes. They're pretty nice also. I will likely purchase one for a ML application.