All I can say is that Yoshi is amazing, I've been playing with this char since SC4, his basic game is the same, good lows, good mids, dick punch, grabs and gimmicks. I don't care how prepared you are, there's tons of tricks to remember, and I know every gimmick, and still would be catched by lots of this, seriously, fighting against Yoshimitsu melts my brain, imagine the rest of the players that has no clue what's going on...
So mix every combo you have, I've sacrificed some guaranteed damage with the purpose that the next time I would go into pogo, I got them ducking for example, and many other mind games.
And people still saying Yoshi is mid tier, that's OK :), whenever I play vs a top tier char like Pyrrha, Omega Pyrrha, Natsu or Alpha Pat, I honestly always feel that I have the adv, but that's just me. The only MU that I wouldn't play is Viola, she is plain broken but some people still like to think she is not, even when Lost Providence has been saying she is broken and proved that in real situations.
Anyway, keep the Namu going, I think that Signia felt the same when he was at EVO, he was destroying everyone until he had to face the broken ass Viola, where he was winning most of the matches, Viola only has to do one read to win rounds. So for me Signia won EVO, Viola is banned for me.