This is the Reg with a supposedly "techie" reader base, so:
1. You don't have to register it *at all*, if you don't want to (SQLitre is easy for the one liner you need to acheive this)
2. Battery life. Even with approx 1-2 hours use per day, and lets say , 2 hours per week with the light on, my Glo is at 25% charged, and I only charged it the night I bought it, 3.5 weeks ago. Try getting anywhere near that with an LCD (and on holiday, you might just not have easily available, a power supply at the right time).
3. Tablets and LCDs are nice for what they are good at, but IMHO are not a patch on eInk for reading. Eye strain on LCD, especially when reading in a dark room, I find quite uncomfortable. The Glo in the dark is nothing like that, and perfectly comfortable for me.
4. Page turns are quick and I can't say I've noticed the "all black" full page refresh, nor the ghosting or other problems, so am happy with the 6-page refresh.
As an aside, my 9y/o child also likes the included Chess, Sudoku and simple drawing software as well.
I've also had a play with the Paperwhite (3 weeks ago, in Waterstones), and thought it was very similar indeed to the Glo. It has a finer grained control of the light, and it's an advertisers wet dream, but I would say they are largely, the same. You can of course buy Amazon books if you don't want an alternative DRM encumbered Kobo book, but you would need to strip the Amazon DRM (which is something I would do regardless if I had a Kindle, for a useable long-term backup).
I choose to "sideload" books regardless (and would also, even if I had a Kindle), so that I am in control of my library, not the device manufacturer. +1 to Kobo for supporting epub (and Mobi) and -1 to Kindle for not supporting epub!