We're on the inside looking out. No, it doesn't "sound" helpful. But, for those on the outside looking in, trying to find something that they didn't know they didn't know, it's a general rule of thumb to go by. And that is helpful.
It's like saying It Has To Be Felt (IHTBF) because IP/aiki is different. From the inside looking out, uh, duh. But prior to my experiences, just like Richard Stevens here, that advice seemed useless because I didn't know that I didn't know. From the outside, if you keep that advice in mind, you look for someone who doesn't move, feel, or act like all the rest of the martial artists you've trained with. You look for something ... different.
IHTBF has to be the most frustrating and infuriating acronym I've ever encountered as an answer... but is so true, sadly, far too true. And most likely, You Won't Feel Anything Special - YWFAS? You have to cast a seriously wide net to find stuff of value, and even then, there are plenty of traps to fall into. As much as it sucks, it is probably better to get used to the fact that, for the most part, this stuff has been and may remain out of our geographic reach, and that if we want to get it, we have to sacrifice a bit of determined in-person investigation and travel expense.
I moved half-way around the Earth to get what I thought was it, and, nope, not quite, better luck next time. And it still took well over a year after the fact for the realization of that to sink in. Live and learn! If only I could have gotten it at my local YMCA, that would have made it pretty easy, eh? But if we don't go out and dig, we never find the gems either.