I disagree. Manning gave everything to wikileaks and they (Assange) and the chosen publishers curated it (somewhat badly). Snowden leaked to Poitras and Greenwald and they seem to be curating with much more care.

This is smart because Snowden can't have access to the archive because it isn't safe for him to have a copy whilst in Russia. It is also smart of Greenwald because the USG are looking for any tiny chink in the armour to be able to descredit Greenwald and by association, Snowden. That's why Greenwald has still only released and estimated 1% of the archive. Each release needs to be analysed, reviewed and judged for release before carefully timing the release for maximum impact. Any damage to the safety of US personel on the ground is going to become a propaganda coup for the USG. Greenwald only has his integrity. Once he loses that it is very hard to get it back, which is why I hope he hasn't made a mistake choosing his FirstLook backers.

There was a reason that Snowden chose Poitras and Greenwald over Assange. Firstly he did his research well. He hoped that these two in particular were noble enough for the task. He knew that both were somewhat ostracised from the US and certainly targets for sigint, and both were living outside the US.

Snowden also let slip his opinion of Assange in the NZ-Dotcom presentation. He said:

  "I think its wrong of any politician to
  take away the public seat at the table 
  of government and say you'll simply have
  to trust us and you know what, its not 
  in the public interest to know about 
  these programmes, unless it threatens my 
  reputation, in which case I'm going to 
  throw documents in the air like I'm 
  Julian Assange. No offence there Julian"

Assange and Poitras/Greenwald are substantially different beasts. What is impressive is that Assange would have been Snowden's easy route. Instead he chose two people who had zero knowledge about sigint and no history of dealing with such a leak. What they did have was class and integrity and luckily that won him over.

They don't throw documents in the air like Julian Assange (for personal reasons). The documents should transcend personal issues.

I think Manning's choice of Assange also demonstrates a lack of 'due regard'.