I always considered the 9.7" Pro the Pro Mini since the Jaw dropping Keynote when they said ALL the features from the 12.9" Pro plus major improvements like P3 Wide Color Gamut, And True Tone and 4K Camera plus more made the 9.7" superior to the 12.9" Pro.
Still on the fence about the 10.5" Pro Must haves are 3-4GB RAM, must see it in person. Otherwise no point in upgrading since the 9.7" Pro Mini can do everything. And it's still the smallest Pro iPad.