I'm sure most on the board will trash your post, but it actually was very well reasoned. You hit on some key items that few who post do since they don't actually do real fundamental number crunching themselves.
1. There are real execution risks they have to endure that are outside of their control by the mine operators that they get their royalty streams from. Last year it bit them pretty good.
2. They didn't raise their production guidance. I was a bit disappointed in this.
3. Your NAV approach is good. It comes down to what the long-term price of silver will be next year. Most posters on these boards come around when the metal cycle is hot and fade away during the weak seasons. They think silver will be this high or MUCH higher going forward and the average price will always be much higher over the entire year. In the end if the ave price is around current 30yr high prices or higher the stock will do fine. If they pull back then the stock will drop back into the $20s.
Best of luck no matter which view you have on the stock...