I know people involved with the Rocketship schools, and I don't doubt their good intentions.
I doubt their understanding of children.
Any schooling that requires a nine-hour day - which Rocketship does - will be successful on standardized testing. I have no idea why this is a question, really. Anything that gets drilled enough will get memorized and regurgitated at the appropriate time and location.
I just don't consider that learning. I don't consider it child-centric, or a good test of whether technology in the classroom works or if teachers should just work twelve hour days by contract.
If your goal is high test scores, it's a working model. If your goal is high-achieving students who write well, are confident, read with ease and discuss it with depth, it's not.
Neither is our current public education system, really - not because it's not a long enough day or technologically advanced enough, but because it is not intended to be so (and is certainly not funded to be so).
Ultimately, I think it comes down to the fact that too many of the people running charter schools don't think much of their fellow man, especially the poor, and aren't really interested in an active, informed citizenry.