Not much of a difference if you're running your JS code through Googles closure (https://developers.google.com/closure/), this basically does a complete re-compilation of your JS, removing dead code, unused variables, and lots of other optimizations, and in the end spits out a big ASCII blob that could just as well be byte code. It has nothing in common with the original source code.
And then you throw JSNice at it, give it to a college student, wait a weekend, and have a nicely readable source version.
Source: Am college student, for fun I disassemble websites, including the funny VM Google built for ReCaptcha.
Additionally, I wonder what the EU thinks about this, as anyone who has the ability to use a software has the right to take it apart, inspect it, and learn from it. This right can not be signed away with contracts (making the "Do not decompile" clause invalid) and is violated by all these closed source web projects.
Tbh, I should probably just decompile, deobfuscate and refactor the Google Inbox client source, and publish it on GitHub over summer break, just to show Google how useless and annoying their obfuscation is.
