The only upside I can see to that provision is that it actually gives the nervous RINOs a chance to "change their minds" and vote "nuclear" if indeed the rats abuse the "exceptional circumstances" excuse for denying a nominee an up/down vote.
The only mind-changing I see RINOs doing is deciding to vote against President Bush's nominees on the Senate floor once Larry Flynt dumps his latest load of sewage on the nominees' heads.
Why were they so afraid to vote for the "nuclear option" in the first place? Without partaking in this silly compromise.
You can bet the mortgage the Demorats will use the "exceptional circumstances" clause until the cows come home. They will invoke it for every nominee for the Supreme Court who is conservative. They will claim "he or she is out of the "mainstream".