I have been looking into charter schools in Denver. I don't know about CS schools. One thing I noticed, that may be true there too, is that there are a lot of schools that are only open for a year or two. So the stability of the school may be a consideration as well. Especially if they all use a lottery and you choose one that closes and then you can't get in somewhere else.
There are some really creative things going on in charters though--it's exciting.