The short answer is to consider an L3C as an LLC plus responsibility to all stakeholders, not just financial shareholders, and limited access to grants (In case you are seeking grants, be aware that many donors are restricted to funding 501c3 non-profits.). Unless you are founding a social impact venture, L3C status (and B-Corp status) might not be worth the additional paperwork. I have contacts who can provide detailed explanations if needed; feel free to e-mail me off list to discuss further.
In addition, note that L3C and B-Corp are certifications by third-party non-profits, distinct from the legal status of 'benefit corporation' as defined according to state regulation.
Hope you had a strong start to the new year!
Post-Hurricane Sandy recovery info: If you are in New York City and need technical help, submit your request via bit.ly/hurricanetechhelp. If you can offer help, fill out a short form at bit.ly/hurricanetechvolunteers. Follow #NYTechResponds, #SandyCoworking, #SandyVolunteer, and #SandyAid on Twitter for updates on relief and recovery operations. For more needs and opportunities to volunteer, check out recovers.org and sparkrelief.org.