As much as the EU has its problems, it was an agreement among nations for nations, with nations retaining sovereignty (the Lisbon treaty introduced majority voting, so that's less true now). It has respect for human rights built in and its courts are, well, actual courts. It has a pretty good track record on delivering on human rights within the EU. I dread to think where Ireland and some others would be socially without it.
The TPP and TAFTA on the other hand, are agreements by nations to hand over some of their sovereignty to corporations and opaque tribunals. The WTO is already this to some extent but is actually about international trade. TPP and TAFTA go much further and impact the laws that can be passed inside countries based on the impact they would have on international investors operating inside those countries.
There are already treaties like this and the results are not good. The Australian govt is attempting to regulate tobacco packaging and is being sued by Philip Morris because it will hit their profits (http://www.bbc.co.uk/news/world-asia-15815311). Tobacco companies making less money is exactly the point of the law. If a government decides to hit tobacco companies and the existing courts are OK with that then that should be the end of it.
The idea that someone has a right to continue to profit from a harmful industry or to be compensated for their reduced profits is nuts. It warps the investment market. Right now, investments like this are risky and capital is allocated elsewhere as a result. These treaties remove these risks by forcing governments to compensate investors who have chosen to invest in industries that end up being regulated. This makes antisocial investments more attractive.
TPP and TAFTA are more of the same, just bigger and stronger. They are being negotiated in secret with only a corporate interests represented. Some parts have been leaked, they are not nice.
You can read an American perspective on TPP here:
This article is about opposition in Japan:
If either of these passes, the other will become much more likely ("we have to follow the international standards, don't you know").
They both need to be shot down.