I picked one of these up last week on Cabelas current sale, normally $499, on sale for $349.00
I havn't had a chance to use it in the field yet, but live in an area where I can range all kinds of stuff, as far as 1650 yards.
Far as ranging goes, I havent had one time, where it wouldnt produce a range and have ranged all kinds of stuff between 1200-1600 yards.

Clarity is excellent, ease of use is a "10" and its nice and compact.
I have used a Leica 1600, which cost twice as much and the sig works just as well. The Leica is slightly clearer, but far as ranging, I dont think it performs any better for the added cost. The Leica does have a few more modes, which may suit some, but it's nothing I would really use.

My only complaint is the 7x power, nice for viewing long range, but a lil tough to hold steady on long range targets.

Overall, I am happy with the purchase