I worked for an LA last year who did a number of reviews. In many cases the school found them to be rigorous as 3-4 advisors would be observing lessons, looking at planning and books etc. Many found the feedback useful and when OFSTED do come along the LA have a good handle on what's going on at the school already. Also, the reports I saw were detailed and gave the schools quite clear targets and areas for development. I also know that a new Head asked for a review. This was perfect for her as she was able to make headway on a number of inititaves before OFSTED came. On the down side, there's a bit of extra pressure on staff as they will be observed!