Avantages
There are a lot of smart people and lots of opportunities to learn from them - frequent tech talks, generally open communications policies. All of the managers I've had have been people that I've felt like I've worked _with_ rather than _for_ - they've been generally interested in figuring out what's needed for our customers and getting the group's feedback on how to get it done. I haven't experienced any of the micromanagement styles that I've seen mentioned in other reviews here.
Inconvénients
Most software groups are responsible for software that is used by a production website or service -- that means that depending on how old the software is or how well it was written or how well its operations were thought out, it can fail gracefully or not. Some groups have frontline oncall support teams, but many do not, so if the production software fails a lot, you may be on a pager rotation that can cost you some sleep :(.