Re: the post about 'technician' WRs who aren't size/speed freaks no longer being true #1s, someone should probably tell that to Randall Cobb, Antonio Brown, Greg Jennings, Reggie Wayne, Victor Cruz, Stevie Johnson, Michael Crabtree, and Cecil Shorts. Yeah, the top 4-5 guys are physical freaks, but historically that's usually been true.
To be a #1 receiver in the league, you have to have several different things that you do really, really, well. Size, speed, agility, hands, route-running, jumping, etc. etc. If you have a physical freak like Julio Jones, then the path is definitely easier, since you're starting with elite size, speed, and agility. If you're Megatron, it's almost impossible not to be a #1 out of the box, since you're starting with elite size, speed, agility, and leaping ability.
But take Antonio Brown, for instance. He doesn't have elite size, leaping ability, or speed. But he has great hands, runs excellent routes, reads coverages exceptionally well, is deceptively agile, and runs every route in the playbook. That makes him a very effective #1 receiver in the Steelers' offense.