k12 has 2 options you should check out before you commit ANY money to them:
1) An extended free trial (their friee trial is only 24-72 hours long -HA! I can't even get my adrenaline down in that time period to to judge accurately, I need at least a week)... BUT if you call in when the trial expires they'll extend it for about a week.
2) Their month to month option is ungodly expensive (about 5x what you would pay for most other things, or twice as much as you would pay for other online type schooling)... BUT if you're willing to drop $30 per subject per month sign up and use that month to test them out. Then at the end of the month cancel penalty free.
I'm not personally a big fan of k12, but I don't hate it like most of the people I know do. Probably because we paid out of pocket, so it was totally at our discretion what and for how long and when we used it. Most virtual academies are VERY strict about those things (like being in school, without the benes of other kids and a playground), and most of the teachers *from what I hear* are rather obnoxious (obviously biased sources, because out of all the people I know IRL and online who have used it -about 250-, only 1 family has every really loved them. . The parent isn't "teaching" (yes they are), but instead is "coaching". Essentially the teacher-option (from what I hear) is the worst of both worlds, at least for younger grades.
As I said, we did NOT have that option. So they were *okay*. Fairly mediocre and VERY expensive, and not interactive at all in the k/3 levels for curriculum. Just workbook pages on a screen with some flip book style graphics. Those pages can be printed out to leave you with a hard copy lesson plan book... but they have to be printed individually. Takes about 4 hours per each subject. VERY tedious. But worth the effort... because if you ever stop paying them, all those records and info go *poof*.
K12 SOUNDED really great when I was first looking at them, but they were a real letdown once I really tried to start using them. The biggest disappointment for US, is that my kiddo is a real hands on/ interactive learner. Some of the edu sites, edu games, and other programs are SO amazing I have to pry him away with a crowbar. This program, though, the most interation he had was clicking the arrow to read the next page (they say parents are supposed to read every page until 3rd, and then it's about 1/2. So not even starfall.com capable of narrating.
But yah. My bias is that I didn't like them, because they didn't work for us. They do work for some families, just not most of the ones *I* know. Their biggest asset, I beleive, is the hand holding during that first couple months to a year where we're uncertain if we can really do this.
But just because *I* don't like them, doesn't mean they aren't perfect for someone else. Hence the strong recc for doing a free trial.