"...is this one of the best risk/reward opportunities around/ever??"
I know you didn't ask me, and excuse me for jumping in here, but I'd like to address that. The answer is, it depends. It depends on what YOU consider "best risk/reward opportunity" to be. In other words, you may feel that moderate risk and moderate reward is "best" for YOU.
Exploration-phase mining companies usually fall into the very, very high risk v. extremely high reward scenario. In this case, the only difference is the reward side is more into the potential of being obscenely high.
In my opinion, this is the "best" lottery ticket around in this sector, and it should be treated as little more than that. You don't bet the farm on a lottery ticket, and you should not bet more on this issue than you can comfortably do without.
Others here, of course, will disagree, saying "buy all you can" to grab a share of this life changing opportunity. But in your judgment, you have to consider just how much you life many be changed negatively, if this does not work out.
This is the only way to play exploration-phase mining stocks, in my opinion. And, I try to moderate my own risk in this area out of advancing my level on the very high learning curve involved here.
Good luck.
VP in AZ