If enthusiasm for the candidate is the most important measure, Democrats get the most bounce from their convention. If you were measuring the quality of the speakers, that was on the Democrats' side too.
Choreographing, stage crafting, and meshing the themes of the speakers, again goes to the DNC.
Leaving policies aside, the vision for America aside, did the DNC get more bounce than the RNC?
Well, that depends on the news source that's reporting on this and what their agenda seems to be.
Gallup reports that Obama's Job Approval is up now after the DNC to 52%- the highest since May of 2011.
http://www.gallup.com/poll/113980/Gallup-Daily-Obama-Job-Approval.aspx

Liberal news sites agree with Gallup. Gallup is independent and non-partisan last I checked.
Conservative news site say, "Not so much".
http://blogs.wsj.com/washwire/2012/09/07/obama-convention-bounce-looks-less-likely/

Moderate, objective sites say Obama leads Romney in 'bump'.
http://www.businessinsider.com/obama-dnc-convention-bounce-poll-romney-rnc-republican-2012-9

Which brings us to CNN's story:
Harsh Realities for Democrats
http://www.cnn.com/2012/09/07/opinion/gergen-obama-charlotte/index.html?hpt=hp_c1

CNN appears to take the harsh view of reality. The same harsh view that conservative news sources seem to be taking these days.
Google 'DNC Convention Bounce" and see what you believe.
David Gergen, CNN Senior Political Analyst, says:
"The president offered up a series of goals for his second term but even they seemed small and lacking ambition.
There were flashes of inspiration but overall, he was tempered and more cautious.
Make no mistake: It was a strong, well-delivered speech --"presidential," as they say.
It just didn't sweep people off their feet the way Obama once did.
Indeed, he was probably lucky that the speech was moved indoors:
it worked much better in a compact arena than it would have in a cavernous stadium.
Mitt Romney and Paul Ryan have a serious chance to win this.
Underlying economic conditions are working in their favor and with the new jobs report, it is easier to make the election a referendum on the past few years. And they have tons of cash to pour into the fall."

David Gergen usually hits it out of the park on his analysis, but not so much on this one.
This was Obama being humble.

Maybe you noticed the President giving the people the credit for the change that has occurred.

This was brilliant.
This speech didn't call for his 'soaring rhetoric', just a summary of the things he was able to get done in spite of huge opposition in the U.S. House and McConnell's 'filibuster controlled Senate'.

And McConnell's most important goal? Was it jobs for Americans? Now they blame the president.

Clinton put it best at the DNC:

"The Republicans left Obama a total mess, he didn't clean it up fast enough, so now they want voters to give them back control".
Are we better off 4 years later?

Sure we are.

Could our recovery have happened faster?

Absolutely!

Had Republicans been pulling as Democrats and Obama were pushing, in the same direction, that would have happened.

Instead, we saw House Republicans dropping logs in front of the car because Obama wouldn't give them the keys to the car back.
Gergen goes on to say that this is a referendum on Obama.

Maybe for you, Mr. Gergen.

Most Americans now see this election as a choice.

One future looks bleak and undesirable under a Romney Presidency.

The other future looks like what middle class see as one of opportunity and hope, and yes, "Change you can believe in".
Just because David Gergen and CNN have become cynical and side with the conservative view of an election on 'referendum rather than choice', doesn't mean the majority of Americans have.
I believe the choice is quite clear and stark- Oligarchy under Romney or a true Representative Democracy under Obama.