Slicing position makes a lot of difference - a lot more than I realized

I am slicing this holder that I designed. I was deciding on the best way to position it to print.

In the side orientation it is 9 hours and 60m of filament.
In the back orientation it is 19 hours and 80m of filament.
Simply rotating the back orientation 45 degrees cuts 4 hours of printing time, but adds to the filament used.
Same model - same settings with no raft or support.

I knew that it mattered, but never paid enough attention to realize that it mattered that much. Can't really figure out why.