We just went in September with my family - 7 adults and 4 kids under 4. We had my parents and all three of us sisters. One sister is single, the the other one and I both have a 3 1/2 year old and an 11 month old. My sister took a joovey and my husband and I took 2 Mac Quests (had to recline for naps!!!). I loved our decision to take 2 strollers. It made it easy to divide and conquer!! I also second the call for lightweight strollers. It's a must!! My sister loved her Joovy - but had issues when her 3 1/2 DS would fall asleep in the front - leaving her to carry her 11 month old DD for an hour or more. When it's hot out - having that baby all snuggled up against you can REALLY raise your temp!! One other thing to note is that my son (3 1/2) is - how shall I say it - independent. It was nice to be able to carry the colapsed stroller while chasing him around the bus stop, etc. My husband could carry the stroller, the diaper bag, and still keep up with him. I had the other stroller, the baby in the carrier and "goodies" bag.
My sister's son actually listens so she had no problem carrying her daughter and the gear while her husband took care of the stroller.
But - to each her own!!!