I'm not going to teach you how to test the device but I would like to pinpoint the critical items I would like to see:
- THE TEST. Period. Carta (H2O) vs Pearl (HD). Go through the very same books and settings with and without front light. PLEASE, thousands of tests, pictures, whatever...
- Carta + IR (H2O) vs Carta + capacitive (Kindle PW2). Kobo should be slightly better because IR is air but Kindle has extra layers on top of the screen. If possible another batch of lots of tests/photographs side by side.
- Quality and building of the USB and SD sealing. Please consider that the USB port needs to be "frequently" opened in order to charge the device.
- Responsiveness. Not really, really critical as Aura HD and H2O seem to have the same CPU. But let's see how page turns go (maybe Carta can win Pearl again despite the CPU) and how HEAVY pdfs or web-pages are handled. Again, a side by side video would be great.
- IR touch precision / responsiveness. I mean, my Aura HD is really really better than my old PRS-650 in nearly all aspects (but stock software design, dictionary quality and the plethora of small annoying little bugs that Kobo always suffer IMO) but nevertheless I've got the feeling the IR precision is maybe even slightly worse. Of course a comparison against the capacitive Kindle PW2 would be also welcomed, although here, Kindle should perform much better because of its technology...
- If you update them to the very same firmware version, tell us which differences you see between HD and H2O features.