Started looking at the Tutorials, but they seem to be the C2 tutorials updated for C3 (not a bad thing). But rather than go through all the remedial stuff again are there some good quick to speed resources for C2 users to learn the new stuff of C3?
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C3 works pretty similarly to C2 in most cases, so I don't think there's much of a need to have a guide on what's different. You can however find everything new in C3 over C2 here, which includes links to relevant blog posts and manual entries. There's also two relevant guides on the manual on importing C2 projects and the C3 runtime, although most changes are pretty minor.