My take on Oakley lens tints:
H.I. Yellow: Great in low light, but not so versatile - as soon as their is a bit of sun I want something darker. Excellent at night, though.
Persimmon/H.I. Persimmon: These are supposedly Oakley's 'do everything' lenses. I agree that they are probably the most versatile in terms of light transmission, but I really do not like the color tint - nothing objective, just purely personal preference/dislike. These are still pretty decent at night.
VR50: My current 'all-around' lens. Touch on the dark side, but still pretty versatile. Like the Persimmon/H.I. Persimmon it filters blue light (good in snow), but I much prefer the VR50 color tint. However, only borderline (at best) at night.
Side note: Most other Oakley lens tints are on the dark side - many people ride with lenses that are too dark. I am always amazed by the number of people with the Fire Iridium lenses on overcast days - fashion over function, I guess...