I never thought it was anything "special" whenever Pinkie had a collapse, myself. I think the fandom just likes to latch onto her portrayal in Party of One as an excuse to paint her as "the unstable one"...low-hanging fruit, if you ask me. (Oh, look, her eyes derp out and she briefly gives a deranged smile. She must be a true headcase!)

The reality of it, as you said, is that plenty of the others have had their moments of mental or emotional instability when they're at odds with themselves. Hell, it happens far more to Twilight, and her "moments" are far more entertaining IMO.

I like analysis and all, but, to be blunt, Digibrony is a huge tool. He has 0 charisma (he's about as interesting as watching paint dry) and seems to have too much bias; I have a lot of favoritism towards Rarity when I review, but the thing is I put it out there like "My reviews are entirely subjective." He's saying subjectiving things under the guise of them being objective.

I'd take everything he says with a grain of salt. He's not really too good - scratch that, he's a pretty sucky analyst. He has no charisma and no objectivity. Boo.

^This. Also he's completely full of himself.

In addition to that, the way he emphasizes the L in talk makes it difficult to listen to him.

I'm not really going to talk about his character. I don't know him.

I am wondering if my appraisal of his argument is correct and my counterargument sound.

I agree for the most part, as Twi and Flutters quite honestly have much more severe mental breakdowns than the others. Pinkie comes in third I'd say; in her case it's the way she goes from one end of the spectrum to the other that can cause people to label her as the crazy one. Pinkie may sometimes get in a depressed state but she is a heck of a lot more stable than say Twilight, E.G. "Lesson Zero", "It's about time", and a couple episodes in Season one which I can't remember the names of at the moment. Or as RD put it in a recent episode, Twi has entire freakout arias.

The Mane 6 are all crazy in their own ways, imo. Pinkie herself is just sporadic, she flips emotions on a hair trigger and has a very scatterbrained thought process, but as a general rule is very intelligent, kind, and morally grounded (not to say that she doesn't step on others figurative toes from time-to-time).