I have recently been on the "Mariner of the Seas". Voyager is an older sibling of Mariner, commisioned in 1999 vs 2003, but should still be similar.
I heard from the crew of Mariner that it would be very similar to Mariner.
So...
Mariner was absolutely amazing. My wife and I had a fantastic time.
The main dining room was a five star dining experience with all the food you can possible eat.
I would say the average passenger age was mid thirties to mid forties. Older than the party goers of Carnival, and younger than the seniors of Holland America.
We were never bothered by any children as they had an entire deck section dedicated to them, and famies on-board rated our cruise as more enjoyable than Disney.
The activities were non-stop, always something to do, or seel, or eat...
We would highly recommend.