I initially bought and installed an ATI stock for my 580, but it had fitting problems and when I spoke to the company they suggested I take a file or sand paper to it, so reluctantly....I did. I got the trigger assembly to slide in easier but once the trigger grabbed on to the receiver, it seemed to pull it very tight. It was so tight, in fact, that it caused the action to bind.
So I sent it back for a return.
I then bought a Tapco, which I use for my 10/22 and absolutely love it. My daughter loves to shoot but the LOP with the wood stock was too long for her to handle. The adjustable T6 butt stock on the Tapco worked perfectly and with the addition of rails I was able to put on a bipod for her.
So using the same logic, I bought the Mini 14 Tapco stock and I am just as pleased with it as I was for the 10/22. Bought myself a fore grip and a bipod for the range, the long top picatinny rail gave me another option to mount my BSA Tactical scope because it has such a massive eye relief I could mount it ahead of the receiver slightly.
All in all, for the money ($100 range), the Tapco is fantastic in my opinion. I like the looks of the Sparta, but my girls are already familiar with the Tapco stock and the fit and quality were superb.