Performance/stability is pretty much the same as the stock from Sprint. Note that there are some differences in the build. For instance, IE6 is included, which can mess up apps that rely on HTMLView (like Weather Watcher Mobile, for instance). Also, this build includes finger scrolling... which can be great, but it also makes it hard or impossible to drag-and-drop in some apps (instead of dragging an item, it will scroll). Other than that, it's pretty much exactly the same as stock. Oh yeah, and Customer Feedback doesn't work, but I don't think we'll lose any sleep over that