But of course u do notice cause most of us have seen the films so many times they commited to memory so any tampering even the slightest of things we notice. To be honest i don't think the originals will ever be released on DVD, its like asking Ridley Scott to release the inferior version of Blade Runner (the one with the Harisson Ford talk over). The whole point of a directors cut is that is replaces the original, u could argue these are special editions. But special editions usually add scenes or include improved special effects, but the whole han shoots first argument is pointless, Lucas has re-edited that scene for a purpose.
So essential these DVD's are special editions/Directors cuts they've replaced the originals.