When I really started to get into doing things myself on my first 911 I remember thinking how uncomfortable I was under it with just traditional jack stands.
I don't have a lift anymore so now I use these for just about everything:
I still have two Summit Racing floor jacks and use four of these (facing opposite) and put under all four wheels. It lifts it up pretty good (I am 6' and 170lbs) and I fit under decent, but more important it just feels safer. I do not drive up the ramps just for clarity. Just use the two jacks and slide ramps under wheels, again, usually facing opposite.
Just did a new fuel pump, valve adjustment, installed new starter and oil return tubes replacement with them. Car sat up on them for nearly a week...
Glad no one was hurt or nothing damaged.
Erik