Pulled up side by side with my buddy's RX8 with stock projector HIDs and did a quick comparison. The Prius's LEDs were significantly whiter, had better spread, and down the road vision. I can't say if my Prius was brighter, since the higher color temperature could be playing tricks on my eyes. The RX8 was an 04, but the lenses are in decent shape. Don't know the age of the bulbs. No pictures as we stopped in the middle of a dark street and had to hurry and move on.
HIDs will always beat LEDs in terms of brightness.......at least to date they will. LEDs have HIDs beat in power consumption
Source lumen spec wise, HID will win 100%. But optic efficiency get into the equation too. HID throws their light in a sphere, LED throws their in a semi sphere, which is easier to focus with less waste. I am interested in which throws more usable light on the pavement, as opposed to the lumen spec for the sources. I am convinced that my LEDs are brighter than the older Nissan Maxima reflector HIDs. I am comparing it to a low mile 2002 garage queen which lenses are in pristine shape. The RX-8, with its better projector optics, is a tougher call.