I had one but regrettably sold it. Also had the VX6HD 3-18-50. Sold as well. The 44mm VX5 was just as good and could be mounted in a lower set of rings. The Firedot is a definite plus.

Currently have all of these either on rifles or sitting or the shelf. Some of them will be leaving as well.

VX6 2-12-42 (favorite optic)
Swarovski Z3 42mm 4A reticle (2nd favorite) and 50mm
Swarovski Z6 50mm and a 56mm sitting in a box.

To my 54 year old eyes, there is not a tremendous amount of difference in clarity or low light performance. The 56MM Z6 is a marginally better at last light but not much. Edge to edge sharpness can vary a little between some. All will get me well passed legal light. The Leupolds have a noticeably better eye box and eye relief. The glass is so good these days, I personally don’t see the need for Hubble telescope on a deer hunting rifle anymore. At least not for me.