Nah I disagree. Some characters definitely have better 6T's. Take Akira and Jacky for example. Their 6T's push the enemy just far enough so you have time to back dash to avoid both WUK options or you can go for the force-tech (33P+K for Akira and 6H+K for Jacky). With Ein's 6T, you barely have enough time to back dash to avoid the kicks since he's so close. And his FT options just aren't as viable.
Definitely his 6T at the very least. you can condition a wakeup with 2K-backwords tank roll but it's risky as hell, miss and you get to see everyone cool crouching throw that you'd almost never see otherwise. it also doesn't work if you know the 2K will put you near the wall