I think his rapid progress has and will be between his ears.....as he learns to read coverages, protect the ball and reduce his alarming turnover rate.
his rocket arm and incredible legs will take him far......his accuracy is what will hold him back.
I view him as a solid starter (in the 10-20 rated area). can't see him reaching "franchise" level (Top 10).
I would use high draft capital (1st or 2nd round) on another QB. injury is all to common for QB's in this league, especially one who runs as much as josh.