Low Molecular Weight vs Sub-Q Heparin?

In the neuro ICU, we do usually just sub-Q heparin and in the surgical ICU, it's almost always sub-Q Heparin. I think low molecular weight is fewer pokes, usually it's once a day, maybe twice in some cases. It's probably a little more effective. These are things that don't necessarily affect patient outcomes but do you guys have a reason for that or it's just what you tend to do? For the heparin? No, not that I can figure out.