Well Barto I'm back watching season 4. I finished season 27, effectively watching the entire series.
Watching season 4 again I recognize what you miss about the show from the early days, I've always claimed here that it remained enjoyable to me throughout and still feel that way, but I gotta admit it was more clever back then. Season post-10 still make me laugh but by different means than the earlier stuff.
Watching season 4 reminds me of how funny Barney was! And on the other hand, Nelson, who's on my top 5 Simpsons characters, was not at all funny back then.
Milhouse is comedy gold forever and always.