IMO, it doesn't much matter for WRs, relative to current expectations. WRs from any system that are currently drafted generally take a year to three to polish their game to the point that they become productive WRs. The first round phenoms come along much faster, of course, but that's a combination of skills by the WR and focus on investment by the team. For the most part, they don't start running option routes from the first day. For the WR position, I think it comes down to atheleticism/body control, measurables, and how well he catches the ball, with some minor emphasis on what's going on upstairs. I really don't think the system should matter much at all, and I doubt that it comes into play much.
People try to detract from the Oilers R&S WRs from back in the '80s and '90s, but you can't tell me that Haywood Jeffires wouldn't be a good receiver in today's game. In many ways, he was an early prototype of the type of WR the NFL moved toward - big, tall leaper. And Givens couldn't fill the Welker type role that teams seem to covet these days? Yeah, I think he'd be OK. Drew Hill was a good WR no matter what. Slaughter came from a different system to play R&S, so we know he could have done it. Now, some of those guys might not have been chosen due to height concerns, but that just shows how shortsighted personnel directors are in passing up guys that can play for the guys that have the measurables.
