See post starting with #33, we were using this and the Doublet you've shown back in 80~90s, don't know where the ideas originated, but certainly was before us.
The Triplett as we've shown has the better overall linearity than the Doublet for a given input, especially 3rd order (as shown by RoGeorge), which was critical in many of our designs and why we using it more often.
The noise is the main advantage over the unbalanced emitter resistors in either the Doublet or Triplett, however at the chip level we could also get better matching with transistors than resistors, altho the Doublet offered a convenient George Erdi Cross-Couple Quad arrangement and ended up with better overall balance as could be "seen" with differential offset.
Intuitively one can visualize how the Triplett allows pushing the two unbalanced pairs further outwards wrt to differential center zero and "filling in" the middle dip of the Doublet with the 3rd balanced pair, and thus achieving better linearity within a given input span, or a wider overall span wrt to a given linearity.
Anyway, fun circuits for folks to play around with
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Best,