Just reviving this thread to say I just installed
Sprint Reader because it popped up as "recommended for you" and I was curious. It appears to be based on the Spritz technology.
I haven't used it enough to really evaluate it but I have read a few pages of a book with it. It's odd at first but I don't feel like I'm losing what I'm reading, I can recall as much of what I've read as I usually can (which is not 100% sadly) I think. I thought I'd hate but so far I don't. Not saying I love it either mind.
Actually what may cause me to abandon it is not the core reading system but the surrounding software. I find the gesture controls confusing and not consistent. You're supposed to be able to tap and let it "read" automatically but sometimes that causes it to stop completely. Also whilst it's possible to rewind or fast-forward fine control is difficult - or maybe I just haven't mastered it yet.
However unlike the Spritz website - which is just a demo - you can load your own epubs into it. Of the handful I've tried it has coped OK with nearly all but one it was displaying code rather than text which is obviously a bit of an issue. I haven't tried it with anything with complicated formatting but then I'd use it for fiction really, which is what I read almost exclusively.
The free version is ad-supported and appears to be capped as to reading speed at about 350wpm - which is above my normal speed so it's good enough to test whether I like it or not.