Even though you may "see" more with ground vis mode and detail lowered, the advantage is , in reality, quite negligible.
I know I am almost given no choice when lots of fires are lit on a base or the "fog of war" comes down at ports. Otherwise my frame rate goes in the toilet. I own a DJ Company and I am running a killer sound card, and more RAM than windows will ever recognize for music editing, mastering, mixing, etc. Sadly, though, in my line of work an "uber" video card wasn't necessary when I built my desktop. I do have better performance in the laptops, however because I use them to play music, music videos, and karaoke. Unfortunately, due to their purpose in life (weddings, parties, mitzvah's, etc), they do not see any internet time (only on local network for library updates and on rare scheduled occasions) I can't afford to clutter them with unnecessary software.
However, lowering detail and using ground vis IMHO does not give much of an advantage. Although you my "see" they enemy easier behind hills, trees, buildings, etc these objects do not arbitrarily disappear physically, only visually. Even though you may see me more easily behind the tree, hill, vegetation, one may be surprised when one's ordinance hits that "invisible" objects and not the enemy.
I honestly find no more advantage to it than shutting down the engine and having a good listen.
As for the enemy shooting you down when you can't see 'em, SHOOT & SCOOT. Never stay in one place for more than 3 or 4 volley's or exchanges. Also, finding a good "hull-down" position always helps.