All most of us have to go on is how they play, what's reported publicly, what the guys are quoted as saying, and what they tell the world about themselves on social media.
I prefer Ballard to Robinson based on what I have observed, but even so, his injuries would give me some pause if I were making cuts.
I thought Robinson played hard, no doubt, but when he tweeted about now his son would never go here or something like that about not getting as many LSU tickets as he wanted, I thought it reflected poorly on him and might hurt the team in recruiting. I follow a reasonable number of players on twitter and he's really the only one I saw pull stuff like that which made it seem worse. There's a standard of behavior that I might expect from people based on my own age and experience and there's acting like a 14 year old girl compared to other 20 something year old college guys. I hope he's grown out of it and has a long and successful NFL career.
I'm pleased both Ballard and Robinson got on the 53 man roster.