I'll have to say I do miss Season 1.
Season 3 is when I really noticed things getting bigger. There were a lot more magic related episodes with detailed plots, etc.
The intensity of the plots built until the finale, where Twilight transforms.
Enter Season 4. The new season started out bigger, partly because Twilight is now a princess and she has more problems to deal with. The 4th season, while still building up to a climax at the end, is still at a larger scale than the others. Now that we have seen Twilight deal with new problems, my hope is that the show will calm down a bit to where it was in Season 1 and 2.
I miss the smaller, less intricate conflicts of the earlier seasons and while I still appreciate the more detailed plot lines, I've found myself a bit homesick for when things were smaller, when Twilight was just a citizen and everypony knew everypony. Nowadays, you have all of the little fillies at the school crowding the restaurant where Twilight is trying to enjoy a meal at, everyone is amazed that the Cutie Mark Crusaders know Twilight, and she can't go about her normal life without somepony sticking their nose into whatever she's doing.
The other characters have changed as well. I've noticed that Pinkie Pie has gone from being quirky but lovable (Season 1) to being a little bit more on the quirky side, but still charming, to Season 3 where she's rather eccentric, and then to Season 4 where she's definitely closer to the crazy side ("Most of my dreams are about frosting! Creamy, creamy frosting....").
I didn't find out until later on that Lauren Faust was no longer writing for MLP:FiM (can't remember how I heard, doesn't matter) so these were just observations I made.
I'm not suggesting that the stories have declined in quality, but I will say that they've changed.
As far as animation and graphics go, it hasn't changed much. If anything it's gotten better over the years.
But one of the other things I've noticed are the songs.
Take a listen to the songs from season 1-4.
(seasons 1-3 and EG)
(season 4)
Notice how much the songs have changed over the course of those four seasons.
The first two seasons have songs in more of an indie style (that is to say, stuff that you could call pop that isn't so mainstream) with mandolin and guitar, orchestral music (usually in a style that differentiates it from the score)
whereas seasons 3-4 have more of a mainstream pop feel. I prefer the style of the first two seasons, as I'm more likely to listen to obscure indie bands than mainstream pop. That's just my opinion, and I'm one brony out of 20 million or so (1).
My guess here is that they're catering to the target audience: 5-9 year old girls. The majority of girls in this age range enjoy mainstream pop. I'm not saying that there aren't lots of little girls who enjoy obscure bands over mainstream music, and I'm not stereotyping. But with 7 billion people on this planet, a good deal of those people would be little girls and a good deal of those little girls would prefer mainstream pop.
No amount of hoping and wishing, on my part, will change the path of MLP. Either it will lean towards a bright and flashy future or it will settle back into a small, happy future not dissimilar to Seasons 1-2. I, an individual in a crowd of 7 billion cannot affect that. Whether or not we get what we're hoping for, we can still enjoy the show.