Putting myself in his handlers' place I'd tell him to accept the tender, smile, work his *** off and be committed to leaving when he hits UFA. Assuming he's as good a player as I think he is, he may well stack another 1,000+ yard season on top of his first two (obviously he could fail as well) which will make him very employable after 2013 and the Giants, again, won't be able to afford his services. So he's very likely to get multiple offers from teams interested in having a receiver with his talent on their roster.
If tendered, he's going to lose out on somewhere between $3 and 5M, conservatively. I would expect Jerry Jones to be one of those interested when Cruz is an UFA and they aren't saddled with the slap on the wrist CAP space they and the Redskins are suffering under this season.
I don't know if Reese can or would even try to make life a little more bearable, as he did with Osi, by giving something above the tender rate. Everyone wants to be appreciated and properly compensated. But if I were advising Cruz, I'd be looking ahead to 2014 as the cards are stacked against us this season. I would not even think of a hold out or negative public statements that went beyond being disappointed. Then it's time to get to work, attend all OTAs, mini-camp, training camp, and play the entire 2013 season auditioning for his next GM, whoever that may be.
All of that being said, Reese may have a plan to sign them both this year by back loading bigger numbers for at last one of them. I don't think John Mara would have gone public saying they want Cruz if that's not true. Now we just have to wait and see.