Does it work better with a different illuminator?
Yes. Also pop out the plug in the lens cover and close cover for better definition.
Do you have a recommendation for an upgraded illuminator?
I use an Evolva IR illuminator, seems a bit bright to me as looking through the Photon and getting it's feedback in the eye can really wear you out. That said I can clearly see animals past 150 yards. I mounted mine on a Weatherby Vanguard using a one piece mount and my sight in was very easy. Bore sighted, put the rifle on a bipod and fired one shot, bullet hit 4 inches left and 6 inches high. I set the rifle back with the dot in the center of the target and with the adjustments walked the dot over to the bullet hole. Fired another and almost dead center so I did the same thing again and perfection. This all said it is still pretty heavy and you really need to have the focus dialed in closely, don't expect to dial in for 100 yards and still have a clear picture at 40. Ok for watching feeders and bait piles.