I love rewatching Yahtzee's older episodes and I do it every once in a while.
While I wouldn't say that the episodes themselves were better then they were later on, I would say that those episodes have more appeal thanks to the unique opening and ending each one of them had. It gave each episode a personal touch and vibe. Plus, it allowed me to get to know many songs that I otherwise might not have heard.
When commenting the issue, Yahtzee said that he thought people were only saying that beacuse they were not used to a standard theme song and that they would get over it once they were. I waited, I got used to it...and I still think his previous approach was better.
In the end, it is Yahtzee's choice whether to use unique songs for his episodes and I am probably the only one that feels that way about the matter. But I really liked his original approach and it's a shame to see it gone.