I'd say that overall, season 5 is much better than season 4. Season 4 was just plain horrible. Season 4 was the only season where I did not buy the DVDs. I definitely plan to buy season 5 on DVD when it comes out at the end of the year.
A few times, it (season 5) reminds me a little of Seasons 1 and 2. One of the great formulas in the early years was that Tony was somewhat 'likeable', and yet the leader of a crime family.
The episode where A.J. got in trouble for drinking wine at school and the flashbacks to when Tony was his age was very good, and showed the 'child-like' side of Tony. Last year I had no sympathy for him whatsoever, and actually hoped he'd get clipped.
They've tried to bring back some of the 'likeable' element this year, though with the twist that the minute you think Tony is being a good guy again, he goes and does something completely reprehensible (like beating up Christoper or almost killing the bartender at his club).
Kevin