The age old argument of industry numbers describing sound quality applies. The numbers don't help define a sound. The 5LE was the first design modification from the original design of the 5s. The 6s were the pinnacle of this effort and the second and final iteration of the original 5 concept. Then the 500s were designed for economics while retaining as much of the final iteration as possible. If the 500s are performing better than the 5LE/6s, it's on lessor gear & you are handcuffing the latter.
But then this ins't a HE thread but a HE 500 comparison to the 800s. On that question, it's a matter of preference. If you would agree that the 800s are a reference of detail and comfort, the 500s are heavier and not as open around the ear physically. The distance of the driver from the ear and the acoustic housing provides the 800s the win in soundstage. The cups are larger on the 800s and can cover a lot of facespace. If weight isn't an issue, the smaller head will like the 500s better and the larger head or larger ear, the 800s from a comfort point of view. I do believe the final word on detail between the two are the 800s but at the cost of a little sonic weight. The fullness of sound and the weight of sound after the initial note I hand to the 500s. This is based on my musical preferences of course. If I were to have to take one or the other with proper gear, I'd do the 800s. I know it's not asked but I take the 6s over the 800s though. The 6s are that much better than the 500s.