I voted for "Not as good, but still worth watching."
It's plain to see that seasons 4-7 are distinctly different in style from seasons 1-3. Whether or not that's a good thing is up to you. Changes in the development and progression of a show over time are completely normal. Heck, it changed from Season 1 to Season 2, and from Season 2 to Season 3 as well. The thing that sets apart the change that came from Seasons 4 and on was the fact that the show was no longer being shaped and developed by the same minds, so instead of the change feeling natural and normal, it feels alienating.
In Season 4, it seemed that the new writers were fully aware of the fact that they had big shoes to fill and tried their absolute best to emulate the style of the old writers. I feel that on the whole, this effort paid off. Season 4 was not terrible, in my opinion; it was a step down from Season 3, but it was decent, and still had quite a few winners, like Krusty Towers and Wishing You Well. At this point, I was thinking, okay. The new writers just need some time to adjust to their position as SpongeBob writers, they're bound to improve once they get the hang of it.
But I was wrong.
I haven't seen all of the episodes in Seasons 5, but I saw enough. I saw enough to know that I was starting to lose faith in the show. In Season 5, it took on a completely different style, so much unlike the SpongeBob that I was proud to be a fan of back at the turn of the millenium. Every episode seemed to have some corny gimmick, cheap jokes, annoying new characters that took attention away from our favorites, plots that had no substance, and just a complete absence of that SpongeBob spirit. I always felt that the confidence of the old writing team shined in their episodes----it was as if the episodes called out to you, saying, "You know we're funny. You know you wanna laugh." However, the message I get from these new episodes is, "We know we're not funny, but please laugh. Please?"
Season 6 and 7, I've only seen a few episodes, and most of them were disappointments with a few good ones here and there. Mostly, for me, it varies. Sometimes, I'll see an episode that's so hilarious it makes me crack a smile of defeat and admit, "Okay, THAT was funny!" And other times, I'll see an episode that's so horribly written it actually makes me shudder. But still, I'll keep watching in hopes of seeing some of those rare good ones that make me feel like all is not lost. But I'm not going to go out of my way to watch and record every single episode like I did back in the golden era. I have this thing where I have to have unlimited access to every bit of canon material about Squidward that exists (it's a fangirl thing ), but some episodes are just so unSpongeBoby that they don't even seem canon to me. Oh well. Like I said, I've largely been disappointed, and I'm going to be honest about that, but I still have hope for a better future, if not a decent episode here and there.