I recently purchased the 3-10x40 Grand Slam. I put it on a 20" A3 Bushy. For the $$ this is the best scope I have used. I'm not a hunter so I can't comment on performance in low light conditions. But on the bench this scope is GREAT!!
It has extremely bright and clear optics from side to side, top to bottom. Has a great single ring focus, no locking ring. I did the 4 corner test and it tracks superbly. Windage and elevation adjusting knobs are finger turnable and are audibly distinct. I didn't notice any movement in point of impact thru the magnification range.
The reticle would most likely be too thick for long range or varmint shooting. It is a hunting scope after all. I've never owned a Leupold so I can't compare the two. For my use out to 500 yds I am completely satisfied. I paid $239 from Bear Basin.
Shabo