More $$: You WILL earn more with AdX just by switching from adsense. You won't near the full potential of AdX revenue without taking additional steps.
I *guess* this could be considered a CON, but only if you are lazy ;) You get the ability to compete other ad networks and your direct orders (I/Os) versus AdX. This is the key that drives up CPMs sitewide.
More Control: You will have control over various items that can dramatically impact revenue and speed performance. This includes ASync v Sync tags, set minimum cpms per ad unit, ability to easily ban advertisers, review ads, etc.
Better Drilldown: If you haven't played around in the doubleclick ad exchange dashboard you are missing out. It gives you as detailed drilldown options as Analytics. Want to know how a specific ad is performing and which advertisers in specific are driving up your CPMs? No problem. Oh yeah, and reports are on CPM not page RPM. :)
Some of the highlights include: Expandable ad units, branding types, buyer networks, deal types, deal IDs, DSP, Agencies, Advertisers, Targeting types, Bid types and the powerful Bid landscape that provides insight into the various bid ranges and how many impressions are filled.
Oh, I forgot to mention - you get direct access to a Google Account Rep AND the Google Acceleration team. Your emails will get a response back immediately.
You aren't a kindergarten publisher anymore - you're in AdOps. Meaning you HAVE to have Google's Doubleclick for Publishers (DFP) (either small business or professional) installed and running. You have to setup your ads according to a logical schema.
The AdX setup is made easier with the help of the Acceleration team, but the initial setup is based on each ad you have. Basically, if you are setting up DFP and AdX you will get a schooling in AdOps and it'll take some time.
I hope this information helps some of you out there.