The Metroline Solo LEDs don't look great from certain angles, certainly not on this day
Events 2013 (Bus Rallies and Running Days) 18 Aug: Hemel hempstead Running Day 7 Sept: London Transport "Reshaping" 45th Anniversary, display and running day, Chingford Royal Forest Hotel 22 Sept: SHOWBUS International, Long Marston airfield, near Stratford upon Avon 6 Oct: Amersham Running Day...
jimmyshengukbuses.smugmug.com
Uno buses have white LED 'blinds' on some new buses and they seem perfectly bright, except for at the rear where they sit behind tinted glass. As you can imagine, they're very hard to read in that situation - but that's not the fault of the display.
LEDs come in all different shapes and sizes and if you see how bright an Infotec display with white LEDs is at a train station, it's clear that brightness isn't an issue if you use the right components.
You can also ensure they're readable at an angle, and even put in an ambient light sensor to adjust the brightness. Likewise, the new displays can simulate greyscales through varying brightness levels.
I do think e-ink with a suitable backlight (again, adjustable to conditions) would work better, given I am sure TfL isn't likely to want scrolling text or anything like that (e-ink is of course terrible for anything scrolling/animating).