Jo Da Plumbr and I went to the range on Saturday and we had some 1911's along. One with an arched mainspring housing, and a couple with flat MSH. My favorite 1911 is a Pre-War Commercial Government Model, and it still has the arched mainspring housing, as does my post war lightweight Commander. I have gone back and forth for the last 25+ years between arched and flat mainspring housings, but have finally decided that the arched MSH feels better, and points better for me. So today I was working on some things in the garage and brought out my Gold Cup and Series 70 Gov't model and changed them from flat, to arched. I realize that flat is the preferred MSH for most people, but I just don't like them as much. So, which do you prefer?