I hope the reactor produces more than 1 mW :-) 1 MW is what is expected...
But the real deal here is very simple. A lab experiment may produce 100W, and it's hard to notice that the experiment consumes 100W from the power outlet, or from hidden batteries, or from stored heat. However you can't hide a 1 MW input, it's just not possible. If the plant produces 1 MW, reliably and continuously and for months, then it will be the only proof that any sane person would care about, and the detractors' whining will have no effect. The proof of the pudding is in the eating.
If it really works, I hope Rossi has excellent security and body armor. I don’t wish any ill on him if it is genuine, but there are people out there that would not want to see this come to market.