Since the team is essentially done in FA already, and we don't need the cap space right away, it may not be a terrible idea to let Suh play it out. That's not to say they should let him go, just finally get rid of the specter of the old rookie scale contracts. We can always franchise him (DT will be about 10 million, very viable) in order to work out something long-term next year. And with it being a completely new contract, rather than extension or restructuring, it will be easier to design a contract that actually fits well within the team salary structure.
If we restructure now, Suh has greater leverage (holding that 20 million over our heads). Signing him next year puts the ball back in our court, where Suh has to decide between taking 10 million (less than he could get in a long term contract and no long-term stabilty) or something longer but more team friendly.
The franchise rage is the average if 5 highest or 120% previous year cap number. That would make his 2015 franchise tag number 26 million with a 35 million cap number. The tag is not an option.