We did the 7 night land/sea with 4 kids and my mom 2 years ago, a week at Disney with the same 7 people last year, and my DH and I are leaving Sunday for a 4 day for our anniversary, SOLO!! At 6 months out the best advice I can give is read the boards, if you are taking children get Kim Wright Willey's book, Disney with Kids 2003 version. It has incredibly useful information about the least crowded bathrooms, ways to get out of the parks with the least hassle, etc. That book is worth its weight in gold. I am a mad researcher...I review all plans, hotels , park options etc. to the point of delerium, BUT, we always get great deals on rooms etc. because I am maniacal. Research, research then research more. It will be time well spent when you get into the park and know your way around, what rides to get on first, and how to maximize your Fastpass options. It's the best vacation ever, have a great time.
Chris