The problem with +1 is that it is not a consumer focused feature. +1 is used for validation of links, sites, articles on Google Search. This makes sense for Google cause it enables them to have a social signal which can be used to better search results. But does it?
+1 takes its inspiration from Facebook “Like”, but unlike “Like”, +1ing something doesn’t really add up to anything for the user. People ‘like’ something to validate, agree, sign, share the specific content with their social graph. But with +1 the consumer doesn’t really have any immediate tangible benefit, which is Google’s biggest failure here. It is likely to be another failed attempt by Google while trying to gain some social cred unless they scale the product differently.
While coming to actual question, will it be a bigger failure than Buzz? Google Buzz was more hybrid sort of response to Twitter-Facebook challenge. But +1 is a response to Facebook’s ‘Like’ feature around which Microsoft is building social search.
Ideal comparison would be +1 vs Like. And we all know who the winner is!
P.S: The above is my answer to a question in Quora
UPDATE- This was written much before Google+ was launched. It makes less sense now, I will soon write an article keeping Google+ & +1 in mind.