I don't think people who are suggesting meet and greets are accounting for the fact that you'd still actually need to eat, nor the fact that the standby times for the meet and greets at Princess Fairytale Hall can be quite lengthy.
So you can do CRT and tackle meet and greets and lunch in one shot, or do meet and greets where you'll be waiting in potentially long standby lines (30-70 minutes per side, depending on the time of day), and then another 30-60 minutes to get lunch at a different QS or TS restaurant. That's assuming you don't want to burn FP+ on Meet and Greets. That's potentially up to or greater than 3 hours just on princess meat and greets and a meal in a worst case scenario.
Personally, I think CRT would be the most efficient use of time as you will get a meal and the meet and greets banged out with one stop, in probably not more than 90 minutes.
I do like the idea of doing character meals on non park days. The fairytale breakfast is great.
The Meet and Greet princesses are Cinderella and Elena on one side, and Rapunzel and a visiting princess on the other. I'm drawing a blank on who it was when we went last year - I want to say Tiana.
We've been to CRT with our triplets (2 girls, 1 boy) at ages 4, 5, 6, 7, and 8 and they enjoyed it last year (it was a request, again). When I was talking with one of our girls about our trip next year, she said she STILL wants to do CRT. I thought for sure we were done with it on last year's trip. But i think a 6yo will get the same, if not more enjoyment than a 4 yo...esp. if they are still asking to do it. Since these are family vacations, we aim to indulge what the kids want to do also, not just the adults.