First of all, congrats for your purchase.
The 1815 automatik is a very nice watch : it's 1mm larger than the 1815 HW, has the zero reset and the movement with the micro-rotor is beautiful. But you don't have the pleasure to wind it every morning.
The 1815 up and down is a nice watch too (Vladimir Putin thinks the same, he has one). But IMHO, I much prefer the classic 1815 without the power reserve : the dial of the mere 1815 is much balanced, more pure.
Anyway, any Lange watch is a good choice !