Shea Weber and Scott Stevens aren't basically the same defenseman. They're only similar in the sense that they're both physical defenseman, and even then, Stevens was a hell of a lot meaner than Weber (although that may just be an era difference). I don't know how much of Scott Stevens you watched, since you were born when his career was already half over. A person can't form any real meaningful impressions, beyond emotional ones, of a player before the age of 10. Now, if you've watched a lot of his games from his Washington days as part of your general hockey fandom, then I apologize. Otherwise, I would suggest that you defer to the people who have more knowledge of the player than you.
Also, there are some great defensemen in the league right now, but I really don't agree that history will look at them as being the same level as the generation of D we are talking about. Are any of those guys top-5 defensemen of all time? That generation of defensemen had 1, and probably 2 (Bourque, Lidstrom). Are any of them top 10 defensemen? That generation had those same 2, and a 3rd on many lists in Chelios. I just don't see it.