257, I had mine for 3 days, so take this review with that in mind.
I bought the 16x version about 2 weeks ago to primarily do an evaluation on it for my new tactical rifle. After reading the reviews on Sniper Country and several other places on the net, I was very excited to try it out. If it was on par with the Nikons and Leupolds, as several of the reviewers stated, I was gonna put it on my new rifle. If it was just ok and didn't quite measure up, I was going to keep it and put it on my Win Stealth 22-250 for varmints.
Well, I got it on a Friday and returned it on Monday. There was a black dot on the inside of the lens about 3/4 the size of one of the mildots. There were also very faint dots running in a line from the crosshair outward. Although disappointed, this by itself didn't make me give up on it. I figured one slipped through QA and I was the unlucky sap to get it. Not a big deal. So do I ask for my money back or have them replace it?
Well, on Sat, I took the scope outside and lined it up against a 6.5-20 Nikon Monarch and a Leupold 6.5-20 VariX-III. I set both of these scopes to 16x and focused all 3 on a tree and fenceline about 550 yds away. Sorry to say, the SS didn't compare. The Leupold and Nikon were much brighter and crisper than the SS. After about 20 minutes of playing with them, my mind was made up. Get a refund and consider my mind at ease.
Maybe it was just that particular scope that didn't perform, but I really wasn't interested in going back and forth trying to find one I deemed acceptable. SWFA was very helpful in processing the return and apologized for the inconvenience. Good folks to deal with.
On the positive side, the scope seems very well made and extremely solid. I really liked the large turrets and the reticle. I really wanted to love this scope, but it just wasn't there. Clarity is a very important requirement for me. Maybe the 10x is much more clear, I don't know. Sorry for not being able to answer your question about tracking/repeatability, but it never made it that far.
Since the return, I decided to pay a little more and bought a 5.5-15.5x44 Nikon Monarch for the Stealth and a 4-16x50 Nikon Tactical for the new rifle. For the money, Nikon is putting out some excellent glass.