Dato - The Original Lange chrono, Pt heft is something to (be)hold, Attractive Triangle layout of date and subdials
BUT roman numerals, black dial with silver subdials and white date background a bit distracting to me
1815 - Arabic Numerals and no date (arguably requirements of a chrono purist), no luminous hands,
But - subdials are too small in proportion, pulsometer and seconds track make it look very busy, cannot lay claim as distinctive Lange chrono like Dato
To be honest, still very torn...but if it was the Pisa vs 1815 WG, my choice would be the Pisa.