Seems plenty bright enough but seen some seemingly crazy claims for light output recently…
The only thing that’s grown faster than the actual brightness of LED bike lights, is the amount by which the brightness of LED bike lights is exaggerated.
For example, a 4 x XML T6 light is sold on ebay as “5000 lumens”. According to the LED manufacturer the most that those LEDs could produce under ideal conditions at max current is 3,600. It’s unlikely that they’re even particularly close to that.
Exposure’s claim of 780 lumens is likely to be rather closer to the truth so you may be surprised by how little things have moved on. Not to say that you can’t get much brighter now, just don’t take the figures too seriously.