I have a Redfield with the accu-range and one without. I have found a great gun to put my accu-range on......my 10/22. I originally got it for my new 22-250 but it shoots flat enough for me that I can easily remember the bullet drop rates and adjust as needed. This is in the East where open area is limited. My 10/22 does fine in the lake when shooting at turtles where I can have multiple shots at the same distance and adjust my aimpoint with the accu-range accordingly.
My personal thoughts are they are a gimick unless you intend to do a lot of shooting out at long ranges, and have time to rangefind your target. The 55gr Hornady's I shoot have very easy numbers to remember out to 400 yards, but between 400-500 yards the drop becomes between 15.9-33.9 inches. How can you make that shot without rangefinding it first? And even with a rangefinder you only have so many marks on the reticle to choose from. If I would have to have a bdc type reticle I'd spend the money on a scope that's calibrated for the cartridge I'd intend to use.
But to answer your question, mine holds zero well. When I first brought it home from the store it would shift poi as I zoomed. After discussing it with Redfield Tech support it was figured out that when it was mounted it was almost at it's limit in adjustment so that when the store bore sighted it they had to dial in almost full horizontal. I removed the scope and tightened everything back down, resighted and it's much better now. I may have 1/2 inch difference at 100 yards between 3x and 9x but that may be from me seeing the target better also. My non-accurange Redfield tracks and holds zero well too.
I think the Redfields and new redesigned Nikon Prostaff are fantastic values.
