The guys at Goodereader.com ran through a comparison the Kobo Aura HD against all of the other major front lit ereaders. I was most interested in their comparison with the Kindle Paperwhite (since most agree that it had the best light prior to the new Kobo Aura.)
After watching their demonstration I agree the Kobo Aura HD has a more even light and a better screen. But if you have not seen a front light in action (the light is embedded in the screen and shines down at the text instead of a light behind the text shining out like on a computer screen), their demonstration is worth watching.
Here is the Paperwhite vs Kobo Aura HD
What may be interesting is this comparison against the Kobo ARC (an android tablet with a traditional LCD display). This is why I am so much in favor of an eink reader instead of an LCD based tablet to read on.