In looking back at the ratings the guys on here provided for these guys, Tight Ends, none of them including Williams were likely to be the next big thing on the offense. There were three that looked like they could be decent picks for the Steelers. Williams and James were two and the third was listed somewhat lower in the rankings. There seems to be a media crush on pass catching from the tight end position rating it much higher than blocking. The steelers have an inverse value with blocking first and pass catching second. Not sure I understand the desire to have passes completed to your slowest receiver, typically your running back is better after the catch as are your wide outs. The tight end might be targeted for a pass 6 times a game by the steelers but he is likely to block in excess of 40 times, seems like they have their priorities correct.
The two players James and Williams are both very close in abilities with James maybe being the better blocker of the two. I think the steelers made the right choice getting him when they did. One other thing I heard on the web was Williams seems to have an attitude issue to deal with, not sure if true or not, but it looks like the right guy was chosen and two other good players were added into the team that might not have been available if they took Williams. That sounds like good planning and being true to your board.