I've been using d.buzz. Things I like:

• It feels like a good way to segregate my short form content from long form content
• dbuzz upvotes the stuff a lot =)
• There's an automatic "post to Twitter" option so I use that when I want to propagate there.
• Posting on Twitter seems to make me eligible for POSH tokens, but I haven't given those much thought
• Browsing by hashtags feels "right" here

Things I don't like or don't understand:

• I don't understand the motivation or mechanics of setting your reward limit, and why the default is 1
• There are some rough edges to the UI