Keith Hennessey was unimpressed:

OMB says the President’s February budget reduces the 2021 deficit to 3.1% of GDP. CBO said the same policies would result in a 4.9% deficit in that year. That’s a big gap, and the same will likely be true here. CBO is likely to say that the President’s specific policies don’t come close to hitting his stated deficit targets.

Hennessey says it "appears that the President’s trigger would exempt more than 90% of government spending from the automatic across-the-board cut."  Will Wilkinson is equally harsh:

[T]he president's approach to the budget is guided by two substantive principles. First, the rich ought to pay more. Second, altering the structure of Social Security and Medicare is absolutely out of bounds—even though marginal tweaks to the big entitlements simply won't suffice to make them sustainable. Sacrifice for the few; consoling untruths for the many. In the end, Obama's fiscal rescue plan isn't really serious.

Well, given our options, shouldn't the rich pay more? How else do we credibly get to balance? And "altering the structure" of Medicare and Medicaid means abolishing them in their current form, right? On this, though, it seems to me the critique from the right is correct: we are talking about major rationing in Obama's plan; in Ryan's, we're talking about cutting seniors off long before their full medical needs are met. I'm not sure which option will provoke the most resistance and therefore eventual repeal. I suspect, given what we have been used to for fifty years, Ryan's.