How accurate a map did you end up with?
For downloading bases, it is an essentially perfect recreation. Some things are missing, such as the color of banners, but for 99% of blocks, just setting the correct blockstates will recreate the build. Some disconnected sections of the build might not be found by the paintbucket floodfill algorithm though, so floating parts could be missing. We counteracted this by having a few random blocks in the chunk be checked on a schedule, so eventually it would get everything.