Disclaimer: styles make fights Linares is more athletically gifted, had one of the best trainers and conditioning coaches, access to better sparring partners, and even faced a DeMarco that knows what it's like to lose but lost. Valero had it in control towards the end, fought through with a big cut over his forehead, and stopped an undefeated DeMarco.
Valero was a very good talent, but I wouldn't neccesarily favour him to beat a Brandon Rios based on what we saw of him. Let's not get carried away now.
Valero was a big hitter but if the likes of DeMarco can take it for 9 rounds, I'd expect a better fighter in Rios to go one better. Likewise, Valero was not a particuarly elusive target himself. He'd have to weather Brandon Rios' best shots too, and the Mexican has shown that he can hit with the best of them at 135lbs.
He didnt show much talent to me. He was a power house and a natural born fighter but not a boxer. (In my eyes). Chin up, mouth wide open and just swung away. He was a B fighter. Even a 40 year old Marquez could beat him.
He wasnt "good" he was thought to be good but in reality his career is filled with speculations of would've and "could've". So Im going to say he had the potential to be good but he decided to be a POS in his personal life.