Nice Article (It brought back a lot of memories). I remember back in early 2011, when the Galaxy S2 released, people were like "Can you believe a smartphone has a dual-core processor?! And that too clocked at a whopping 1.2 GHz!"
And then for 4 straight years since the original Galaxy S, there was a constant trend. Each S flagship doubled the core count and the subsequent Note would increase the clock rate by approximately 0.2 Ghz.
Galaxy S: 1.0 Ghz single core
Galaxy S2: 1.2 Ghz dual-core ----------- Galaxy Note: 1.4 Ghz dual-core
Galaxy S3: 1.4 Ghz quad-core ---------- Galaxy Note2: 1.6Ghz quad-core
Galaxy S4: 1.6 Ghz octa-core ----------- Galaxy Note3: 1.9Ghz octa-core
This trend was finally broken by the S5 and it's 2.5 Ghz quad-core, but now the upwards core count trend has been picked up by Mediatek but unfortunately it's been getting mixed results and hasn't seen the same success as the chipsets used in Samsung flagship.
18 months using S810.
No heat issues.
Good battery life.
"the RAZR i XT890 (one of the early superminis)"
NO, your memory fails you.... it was a quite normal size at the time. Back then (2011) the SonyEricsson Arc with its 63mm was considered an almost absurdly huge phablet, that people laughed at. (In 2017 it would be considered a super compact though...)
Back then the 53mm SE "Ray" was considered a mini, and the 57mm SE "Neo" was considered normal... (all three SE were logically almost identical, except scaling)
I like apple's take.. Just 2cores with more power and less cores means less battery life is taken.