The minus part is that you have a lot of human error. I mean, YOU try to transcribe Marlon Brando mumbling for three hours. Another minus, you don't get to see the original vision the writer had, for the studios just love to chop even more than Lorena. The script and drafts, which is a copy of an actual script at some stage. The plus part to the script and drafts are that you DO get to see the original visions.
Drafts are especially fun because it's usually VERY different from the final script.
And besides, scripts are always better because you get the full text of the script, with descriptions from the writers hand, not some Cheez Doodle-eating transcriber. Next to the script type, is the file size, which is self-explanatory. And then after that is the location of the site that is housing the script. You should visit them after you've raided my place completely. They offer absolutely nothing you can't find here, and a few had the nerve to actually cut and paste my html code and claim it as their own.