No doubt, he's definitely faster, but Welk was fast as fukk too. We've just gotten used to the concussed Welk these last few years.
You make a great point, that we are looking at Welker thru concussion-colored lenses now, but Edelman has been lights out. Dude is fast, tough, and lines up outside. He had a game where there were essentially every other credible WR was hurt, and he still racked up his catches/yardage with the defense knowing the ball had to come to him.
Wes has been put in that position once Randy was doubled and the defense looked down the rest of the field, dude was useless.