It's just so hard to predict durability.
Jake Long had no injuries in college and, after two very impressive seasons in Miami, injuries took their toll and ended what could have been a great career. Frank Gore had that big injury in college, dropping him to the third round, and he's had a long, productive career.
All things being equal, you go with the bigger guy. But the thing that stands out to me with Smith is his easy separation. He has that gliding, easy speed that can fool people. I was impressed with how he stepped up his game when Waddle went down. All the attention on him and he was up to the task. I think he has everything you look for except size. If he were 15 pounds heavier, I don't think people would be talking about it.
Don't know if Smith will ultimately be better than Chase or Waddle. But I'd love to pair him with either guy. That would be a winning draft.