Oh-- one major difference between k12 and Connections is that Connections usually has VERY hard semester/schoolyear endpoints.
One big bonus with Connections is the literature elective for GT in grades 3-8.
That one is a keeper. It's truly differentiated. Based on the Junior Great Books program, this is a twice-a-week elective that runs from October through the end of the school year and the kids genuinely interact with one another, do fun projects and discuss the reading selections in a kind of fluid format under the guidance of a teacher.
It's been the single best experience of my DD's educational career.
