I've been in the market for a good spotting scope for a few years and I've had a heck of a time finding one that I like. I had pretty much decided on the Leupold Gold Ring 12-40x60 when Cammo Fire had a sale on the Mk 4 12-40 for $850. I've had really good luck with the 2 Mk 4 scope I've had, so I figured the spotter would work just as well.
I was a little nervous, but I have to say that I absolutely love it! The glass is excellent, which I would expect at this price point. It's bright and clear right up to the edges even at 40x. I actually really like though. I took it out on a hike last weekend with my Father-in-Law to test it and we managed to spot a deer at nearly 2 miles (this was ranged using a GPS, so draw your own conclusions about how accurate that range is). We were able to make out antlers, but not count points. I was just amazed that we could pick up antlers from that range! The focus and magnification rings are easy to use and require just the right amount of effort to turn them. I've looked at some optics that had adjustments which were either too difficult or too easy to turn and they drove me nuts! The eye relief is probably the greatest feature about this spotter. I can easily look through with my glasses on, and still have eye relief to spare. This alone made this spotter worth the money.
The Mil Dot reticle doesn't get in the way while trying use the scope like I thought it might. It actually helps to give some scale to what you're looking at. I would have chosen to have the TMR reticle (to match my rifle scopes) if that had been on sale, but the Mil Dots still works well. We tested the reticle out to day while out shooting. Since the reticle in the spotter and in my rifle scopes are in the FFP, we were able to easily give corrections to each other without worrying about being on the correct magnification for the scale of the reticle to be accurate.
My overall opinion of the spotter is that this one is a keeper! I'm not certain that I would have spent the full $1600+ for it, but I'm very happy with what I got for the money I spent. Plus, I know I can make my money back if I feel the need sell this spotter. That's always a plus!

Andrew