I’m not surprised by the dramatic variances in experiences with the Sig. That mirrors my experience with Vortex optics for the most part; I’d have one that was disappointing and then a buddy would have one that was great. It seems like a QC issue to me.
I’ve settled on a two rangefinder set. I have the Terrapin for extreme ranging when I’m just out messing around and a used Leica 1600 that I picked up for a good price that comes hunting with me. Since very few people have a real, consistent use for a rangefinder capable of giving a range beyond 1200 yards I don’t think there’s much reason for the average shooter to worry about the ability to range a rock at 3000 yards. Even though I smile every time a get a reading on my stump at 4489 yards, I don’t have any practical use for that information. I do however have a use for a small and portable rangefinder that will give good readings to 1000-1200 yards max. Heck, I’m happy with 400 yards for my hunting rangefinder. I’ve never shot a big game animal beyond 360 yards!