It's not so much "better" as "different". Well, no, I think it's better (and several others will, too) for a variety of reasons. (1) The e-ink technology is an entirely different viewing experience -- not everyone thinks that this, alone, is worth it, but I do. (2) It's designed to do one thing (mostly): reading. So there's no touchscreen, no softbuttons constantly getting reprogrammed, or whatever. There's buttons for page forward and page back, and that's all they ever do. That kind of thing.
Again, not everyone is going to find this superior -- I do, but I'm not a power iPad user. I think if you are a power iPad user, you (a) get used to the screen, which, for an LCD, is quite nice, and ( you get used to navigating within the confines of "that world" (iPhone/iTouch/iPad/touchscreens). So the advantage is not as much, and therefore outweighed by the weight of having two devices.
(Others feel free to pipe in, this is just my observation of iPad vs. Kindle society -- and yes, I do realize there are people who have both, and that having both sort of undermines my argument, so you especially, feel free to speak up.)