"Generally people who drive a hard bargain are either looking for suckers, or know what they have."

In this case, should another party sign a cofidentiality agreement (CA), they give up nothing.  There is no bargain, only a promise to keep quite about what they see, should they choose to take a look.  There is nothing in a CA requiring they do so, or if the do what level of scrutiny will be devoted (i.e., 5 minutes, 5 days, or 100). 

As a 5-year CA costs an interested party no more than a 2-year CA, and does not include a promise that any level of DD will be done with it, why on earth would any claims holder risk losing prospective future claims by doing a 2-year agreement?  And I don't care what some nameless persons in Vancouver or Denver have to say about it.  Why don't they come here and post their arguments themselves?