Pros
Extremely flexible work / life balance. Huge opportunities to make a difference, if you care to. Money isn't the issue in persuing large projects and initiatives, it's generally whether or not the technology even exists to get the job done at this scale. It's nice to be able to not have to worry about whether or not there's budget, if you're even somewhat forward thinking, you can plan for and make it happen.
Cons
Acclimating to Dell can take some time. It's kind of "Here's your cube, your laptop, good luck"... Don't like your boss? Don't worry, we reorg every 3-4 months. It can get really frustrating with staff rotating and reorgs constantly occurring, you get really good at recommunicating the same information 50 times every other month and things can take ten times longer to get done as a result.