(Late reply is late)
I loved My Little Pony when I was a kid, even though I enjoyed the toys (the G3 ones) more than the cartoon. I watched My Little Pony tales sometimes, but didn't watch G3 a lot.
I do, however, remember "A Charming Birthday" and, as bad as it sounds, I enjoyed it. But I was just a kid after all, and found it was fun and heart-warming.
Now? Well, since My Little Pony has gotten popular again, I started watching FiM and saw a lot of criticism on G3. I didn't know what was wrong with it at first, but when I compared it G4, I started to understand why.
Unlike the G4 ponies, G3 ponies were overly girly, had bland one-dimensional personalities (other than being as sweet as sugar to each other) and didn't have great story lines compared to G4. I'm so glad Rainbow Dash was given a huge character make over, because now she's a fun, energetic pony who enjoys adventure. She's a lot better than the G3 pony, who constantly had to say "Rainbows darling, rainbows!" in nearly every sentence she spoke. Sure, I may not have watched a lot of G3, but I re-watched "A Charming Birthday" (Well, tried to, it was hard to tolerate it, especially with the constant "yes, yes, yes!") and a few clips from a few others. Needless to say, it was boring, predictable and like I said, uninteresting overly girly characters. Oh, the horrors of the past...
So, other than the toys (Come on, the G3 toys were at least nice. Kind of wish I hadn't given them away now) and the designs (The colours aren't great but the way they look isn't that bad), G3 is pretty bad, and god knows why I liked "A Charming Birthday" so much back then (I didn't even get much nostalgia from it). I guess I'm just going to have to come to this tragic conclusion that I clearly didn't have much of a brain back then.
Anyway, those are my reasons for disliking G3, which I'm sure a lot will agree with. I only vaguely remember seeing G3.5 when I was younger, but never watched it. But just looking at it gives me a headache, so I'm not gonna torture myself.
Sorry if I made this too long ^^;