my previous subaru (f-xt) had its windshield replaced twice too. oem glass is pretty crappy, but at least fits like it is supposed to (and has mounting hooks).
aftermarket tends to slide down after install, even though they put tape over to hold it in place. increased wind noise is the unfortunate result.
some mirror clips do not fit the oem mirror mount correctly, so test it prior to installation. sun visor/block green stripe is also usually different from oem (much slimmer) and the black dots are larger and poorly spaced.
make sure to inspect the glass before they start the install.
in general, auto glass is much weaker around the edges (less flexibility due to glass resting on the frame), so it is more prone to cracks and chips when hit elsewhere then in the more elastic center area.
btw, carlex (TN facility) makes oem legacy glass. since they are one of my customers i will try to ask the engineers why the glass is so weak
... might be due to subaru's design constraints (weight, thickness, or just lame manufacturing standards/requirements)