I just finished the EMBA program.
To address some of the posts above and to talk about positives and negatives;
In regards to networking - the EMBA is about 100x better than either the day time or P(rofessional)MBA. The reason I say this is because let's face it, the people in the EMBA are generally established in their careers. I can't speak for all EMBA's, but mine had very high level people, including S(enior) VP's, CEO's, and and business owners. The amount of networking I have had has been invaluable. In addition, because of these "high" level people, many of the guest speakers we got to come in talk to us were very high level. As an example, we had the CEO's of JetBlue and Overstock.com, congressmen from both the House of Representatives and Senate. It's great in these small settings where you have lunch with these movers and shakers, and get to pick their brain, ask intelligent questions, etc.
Stronger ties - since most EMBA's are structured programs you go through the entire program with your class of 50 or 60 people. These are ties that bind. I still regularly do things with my classmates. We usually have lunch at least once a month and have parties about once every 2 to 3 months. My friends in the regular program hardly talk to most of their classmates due to only seeing them on a sporadic class basis.
Leadership - because this is an executive program, our courses were focused more on leadership, which is great if this is the path you want to go down. I received a promotion after my MBA and now manage 4 departments. These leadership skills have been invaluable in helping me succeed at work.
Negatives:
Academic rigor - because of the wide range of people (and ages) going to an EMBA, I didn't think academically it was as rigorous as it could be. That's fine in general because I think an MBA is to network and rub elbows, and I did get a lot of the program having an engineering background but if you're there to really understand how to create a balance sheet, or how to do business stats, this isn't the program for you. You'll learn how to do all of the basics, but that's it.
Leadership - if you're going to get an MBA but don't necessarily want to go in to a managerial role then you'll find that an EMBA will unduly focus on leadership and touchy feely issues. This may drive you crazy as it did many of my classmates.
Expense - it's an expensive program. If you can't find a sponsor, it's gonna cost you a lot of money. My program was $38k, and my company paid for 1/2 and I thought that was tough for me to stomach. Others in my class footed the entire bill themselves. Others had it paid for completely by their company. I just heard that the tuition price went up to $42k for the year behind us, so it's not cheap.
Hope this helps. Feel free to PM me if you have any specific questions.