When comparing Desura vs Humble Widget, the Slant community recommends Humble Widget for most people. In the question“What are the best distribution platforms for an indie desktop game?” Humble Widget is ranked 6th while Desura is ranked 7th.
Ranked in these QuestionsQuestion Ranking
Pros

Pro Strong Linux presence
Linux support is a core feature of Desura. All games in the storefront are tagged as to whether or not they will run on Linux.

Pro Alphafunding permits sale of works in progress
Desura calls their early access program "Alphafunding." Games must show a minimum level of development, and must show active development or risk being removed.

Pro Indie Royale bundles can boost sales
Indie Royale is a joint venture of Desura and IndieGames.com which sells bundles of games on a pay-what-you-want basis (but with a minimum price). Most games sold via Indie Royale bundle are Desura titles.
Pro Self-service access to sales data, gift key generation
Pro Grants access to customer email addresses
You'll have access to email addresses of anyone who has bought your game.
Pro Great revenue split (95/5)
Best revenue split available.
Cons
Con Desura's Parent company filed for bankruptcy
Con Must apply for access
Con Bring your own web site
If you don't have a site already, you'll need to get that setup first before you can use the Humble Widget.
Alternative Products
