Hmm. I'm letting this rattle around my head. I'm going to avoid your mobile handset example both because you know more about the ins and outs than I do, but also because the OP mentioned that the one exception to his rule is Apple and I don't know how to talk about what happened in the world of mobile handsets without talking about Apple. :D

I feel like a few things are being conflated. For example, it seems like you're treating "the set of products marketed and sold a lot more on how they make the buyer feel" as a subset of "products that are more-or-less interchangeable." That is, if consumers can reliably differentiate between products based on "empirical" metrics, they will. If they can't, marketers have to resort to "branding tactics" to create the appearance of more differentiation than there actually is.

I'm skeptical because it seems too consistent with how engineers see the world. The world doesn't seem this discrete to me. I guess I see it more as, "Prefer playing along a new dimension rather than playing along a dimension someone else already owns." To me "different" means "playing along an orthogonal axis" while "better" means "trying to outdo someone else along an already-claimed axis."

Here's the game theory version of what I was trying to say. Your brand position is a good one if it resonates with potential customers and none of your competitors can encroach on it without running the risk of weakening their own brand position. A competitor staking out an opposite brand position in a particular dimension is the most extreme and obvious instance of this, but it's not the only one or even the most prevalent one (IMO).

I agree re: CPG. They're hard to differentiate because they live in such a low-dimensional "brand space," so marketers (who need to differentiate them) go crazy. Bottled water for men! For women! From the mountains! From underground streams! From reclaimed bird urine! Whatever. Physically speaking, there's very little to ground these claims in. Source, material, production process, and maybe a few other things I can't think of. There's a kind of fun, wild west aspect to inventing a new drink or other CPG that takes off. It seems like pure theater to me.

I also agree with you that a claim to differentiation grounded in reality is an easier thing to pull of for those of us, like myself, who are no Don Draper.

But let's take another market where feeling is at the core: fashion and apparel. I don't think it's fair to conflate what the hypothetical bottled water brand is doing with what fashion brands do. I'll give an example from Everlane, a company I was very involved with early on.

"Radical transparency" was one of our brand pillars from the very start.

First, this isn't a case of "water from the mountains" vs. "water from an underground stream" or "toasted cigarettes." Everlane is actually touring factories in China and Europe, taking photos, interviewing people, etc. It's grounded in a real, physical difference, although not in the product itself. In fact, part of our story is that we use the same factories that top brands do. However, it is grounded concrete actions that Everlane is taking, but our competitors aren't. Our customers have access to something they didn't before, viz., insight into the production process.

Second, take the OP's original advice: "Don’t say things if your competitors can’t say the opposite."

What competitor of Everlane, present or future, would say the opposite? "Forget radical transparency -- we're radically opaque!" "Buy from us! We like hiding information from you about how our apparel is made." Nobody is saying that and nobody believes that. Who would brag about that? Everlane wasn't able to get away with this because we're Apple or anything approaching Apple, either, so we appear to be an exception to the OP's rule.

Even so, very few of our competitors can say "We're transparent!" Why? Either it's inconsistent with their existing brand, e.g., they deliberately cultivate an air of mystery super chic blahdeblah, or it's consistent with but ultimately unrelated to their brand. In the former case it'd be suicidal for them to say it and in the latter it'd both dilute their message and run the risk of validating our market position.

The great upshot for Everlane is that if you imagine the web being a tribe, one of the things it values (culturally) is transparency and access to otherwise-hidden information. That was the mindset that led us down the path to radical transparency, not any thoughts about product features.

I think this is just as true of fashion and apparel as it is of consumer tech and I think lots of folks in consumer tech miss it because they imagine everyone sees the world in the same product-centric way they do. One interesting thing I've seen is that consumer tech startups from NYC are much less likely to miss these opportunities than consumer tech startups from the SF Bay Area.

That's the best picture I have in my head right now. I just felt the OP's rule left a lot of opportunity on the table.