Very bright, just as bright as the stock indicators if not more so. I have a mate with stock indicators I will try and take a photo of both side by side for comparison. The only issue is you can't see them well from the side, stock indicators can be seen from the side more but these LEDs are forward and back only firing.
I was considering R&G aero indicators as they have an LED on the side but fitting put me off due to lifting the tank and there was uncertainty over whether resistors were required or not.
I got mine fitted on the new bike so fitting was free. Although the aeros are half the price, if you factor the fitting, adapters and resistors they come out the same.
I may change to them later though as I start doing more.
Got the comfort seat today as well, looks better than expected.