My Take
I like the set up of iXl and the fact that they not only have current state standards but also the common core standards that are being implemented. I like that the trial time is daily. If I can have a kid practice for 10 minutes a day, that is 10 minutes more than they would have spent otherwise.
How I Use It
I use it primarily to help me understand some of the common core standards that may be open to interpretation. I also use it to engage my more advanced students who are already comfortable with the current classroom content.