I've said it before, there are lots of reasons why robert's tools are all mediocre:
His A uppercut lacks lower body invincibility. His C uppercut, although invincible, starts up slowly and can easily be safe jumped.
His command grab does not convert to combos. It is also slow and lacks any invincibility. His EX command grab scales everything extremely hard, to the point that it's not even worth using, unless you do it raw in the corner.
All of his far standing normals whiff on crouchers, except st. D. Stand D has horrible recovery. This makes Robert's midscreen footsie game risky in every instance, as he either has to commit to a fast low (A or B) or risk getting hit by a low if he throws out st. C or D.
His fwd A. is completely unsafe on block. As time goes on and people learn how to punish, this tool will become harder and harder to use.
His dive kick is completely unsafe on block unless you hit them at the ankles. The practicality of this move for offense is just non existent as of right now, unless you use the EX version. Even at the ankles, no version of his dive kick grants frame advantage.
All versions of his flying kick are unsafe, although most characters require meter to punish the B version. All versions of lighting legs are also unsafe. On hit, EX lighting legs gives the opponent over 50% meter and close to 50% drive (WTF??). Even though you can drive cancel his regular lighting legs, THEY DON'T GRANT A JUGGLE STATE and Robert has no anywhere juggles (srsly, WTFF???). When you think about it, although he has lots of tools, many of them simply aren't that great. The ONLY special move he has which is consistently safe on block is his point blank fireball, which you must cancel into.
His midscreen HD combos are ridiculously space positioning specific. He has optimal combos at every range, but these combos change and won't work if you are one character length left or right of exactly where you should be. The only combo that works at all ranges within 80% of the stage away from the corner involves using EX lighting legs. He has no coast to coast HD. Doing this combos give the opponent 2.5 bars and 70% HD meter, which is ridiculous. It simply requires wayyy more effort to optimize his HD combos than it does for ANY of the top tier characters. Also, I don't want to complain about execution, but his drive cancel dive kick from C uppercut is quite hard, and easy to screw up. So are his C uppercut drive canceled into A fireball and midscreen A uppercut drive canceled into A fireball for juggles during his HD. These cancels are all NECESSARY for his optimized HDs.
His wall jump is really cool, but when people start anticipating it (and they definitely do!), you really can't use it for mixup. No matter if you just jump back or jump back wall jump, either way people can jump with you and hit you, or just stay on the ground. My training partners can attest to this. It's one of those tools which, like his fwd A, will become less useful as opponents become better at punishing it.
These are all the reasons Robert sucks. Obviously, even in this game being bottom tier still means you're viable. I'd put Robert in the low B range in terms of tier. With this said, he has some awesome things. His j. CD has so much horizontal range and is soooo fast, although it whiffs on crouchers. His sweep is also fast and has great range. His EX ranbu super is also gdlk because it's invincible. Of course, who doesn't fucking love taco crossups? However, when you consider these "good tools", they still pale in comparison to many other top and high tier characters.
There you have it people, that's my full blown opinion on Robert. I'll still play him, just because i've invested so much time into him. But, imo, anyone who says "robert is a great character" is wrong. He's mediocre at best.