I sincerely doubt the final product of TFA was about 70% the same as the first draft.
I think it was pretty close. I also think there weren’t that many drafts, either. I think it might have been something like 2 1/2, haha.
That’s about 1 1/2 more than Attack of the Clones got
I mean, just offhand - originally the film started with Luke’s hand holding the saber in space and went into a whole flashback montage, the saber was the McGuffin instead of the map, Poe died, Maz went back to the Resistance base with the gang, the Resistance had the Sledgehammer ship/weapon - and these are all things that were in the Abrams/Kasdan draft. Who knows what other things were different in Arndt’s version (at the very least we know originally Luke showed up for the climax), but there were other notable evolutions along the way (including the introduction of Starkiller base, making Finn a stormtrooper, and Kylo Ren in general), though it’s unclear if these were fully developed before the first draft or not.