I once imported 4 Leupold Comps from Premier Reticles, 2 40x and 2 45x.
The idea was to assess them and keep the 2 that I liked most.
I sold the 2 45s because the image was significantly darker and it was harder to locate the target.
However if you judge them as a range finding tool the 45s just edged it.
Having said that the current FT World champion uses a Leupold Competition Series 45x.
I have no root vegetable experience though but parsnips are my favourites.