Anyone have experience with Discovery Science Techbooks?

Yes, quite a bit.

Are they okay for a kid to work in independently?

I like DS6's school but the science can be pretty dry with lots of "label the parts of" worksheets. My idea is that he could work on his iPad in the Techbook as enrichment/differentiation.

Definitely, that's how my DS has used it. It's setup as a reaource in sections of topics. He watches videos, does the vurtual experiments. The glossary is built-in; so, you don't get thrown off by new terms while reading. It weaves in a scientific inquiry approach.

I noticed the Techbook for science is K-8. Are all parts of the book open or can some be locked? I am just worried there might be some junior high level content that isn't necessarily appropriate for his classroom. I have this fear of DS leading a lecture on human reproduction with the visual aids from his Techbook in his K/1 split class.

I've never looked for that ability. I know teachers can setup courses and assignments and add content. I'll see if I can find out about restricting content, probably won't get an answer until Monday.

I skimmed through the content my son has access to for 7th grade and 8th grade. 8th grade has a genetics components and some about animal sexual reproduction, with segments on mating rituals for a tree frog and some bird. The glossary entry for sexual reproduction has a small video of an egg and a sperm. Nothing about the human biology part.

I know different states can organize content differently, though.

p.s. KJP, I pm'd you.

Wait. That's not okay?