From my own experience (4 kids, 7 grandkids), I'd say make it the stop-and-chill--it should be the kids' hike, not yours, especially at that age. You want them to enjoy the experience,not be turned off hiking for life. Time and distance goals can come when they're older.
On the home page of this site is an excellent article, "Hiking with Children" by Penny Schwyn.
Required reading, IMHO!
The most important part of the article:
"Kids will force you to alter your sense of accomplishment and to be flexible. For many children, it's the journey that's important, not how long the journey is. They are slower and closer to the ground, and by taking the time to look at the world from their perspective, with their sense of time, wonder and their short attention span, we learn lessons for ourselves and build real foundations of a love for the outdoors with our children. For all of us who have taken young children into the woods, it is the sense of wonder and altered time that seems to be recalled most fondly."
There is also a section in this forum on "Hiking with Kids" where many of us have recounted our own experiences with our children/grandcildren.