I've seen enough of Watkins to come to what I believe is a decent conclusion. I don't think Watkins will ever be elite. I think he is a good to very good wide receiver. Maybe a second tier guy, something like a 1B.
Watkins is an incredibly athlete, that is what led him to be drafted so high. He was a world class track athlete and it shows in how he runs. But he plays a little stiff in the hips, and that's going to keep him a notch below the greats. It's no offense to him, there's nothing he can really do about it. This is at least what I am seeing, others may have different opinions.
As for Goff, wow, I'm fairly speechless. He LOOKS like a ten year vet on the field. And remember, his mental clock will speed up even more and more. I think he's already ahead of Wentz.