Speaking of tiers, I've never understood why Gief was considered low tier. He consistently out pokes me, parries with flex into SPD constantly, and then once you're down 50% he just dashes up or empty jumps into an instant super. Oh, and don't even get me started on how BS his V-Trigger feels.
He is really bad against chars with good normals. Only cr lp is really really good but it doesn't combo into anything or at least into anything good. The loss of green hand makes it hard for him to apply pressure after SPD. And lariat no longer being a gdlk AA removes anotehr knockdown option. Like any char he does well against some chars that rely on up close but when it's a bad matchup it's really bad since the opponent can usually get away and keep him out.
V trigger suction is tricky. If you block the suction, then it makes no hit sound/cue that means he is -6 so mash throw. If you block it then you will be pushed away.