It's not quite as great as it once was, but it's still pretty damn good. McCoy has definitely mellowed over time (which is reasonable because I could see him being close to being disbarred on more occasions than the one time they tried it).
As for character stuff. Homicide definitely did that better. Law and Order tried it a couple of times (Aftershock being a good example), but, in general, the audience didn't like it.
Speaking of DVDs, I bought the first season, since the Ben Stone episodes are rarely played on TV. I've been meaning to get one of the early Jack McCoy seasons, but I'm not sure which one would be the best.