Pros
There are some incredibly passionate staff members and volunteers who are committed to JDRF's cause. If you have a personal connection to type 1 diabetes then it can be an incredibly rewarding position. Great benefits for those with diabetes (100% coverage of all diabetes supplies.) and cumulative vacation days that transfer over each year.
Cons
JDRF is a bureaucratic mess. Limited opportunities for internal career advancement based on the organizational structure. Most chapters are so under-staffed that you end up taking on 12 additional responsibilities than what was originally in your job description (of course, that's the nature of working at a non-profit, I suppose.) In my experience, the most passionate individuals who join JDRF tend to get overworked and under appreciated and end up leaving as a result.