I prefer the Speedmaster in the original size and manual, automatic and big size lost the speedmaster soul, the first watch on the Moon must be manual, if you want a big watch and automatic, i'll choose a Planet Ocean.
I have a Speedmaster too, but a very special for me, is a Limited Edition of 1975 with meteorite dial, The Speedmaster Apollo-Soyuz, I love it!! I have it since 2010 but i never worn it.