The hand-me-down phones we let the kids use as glorified iPod Touches are iPhone 4S (as we upgraded to 5S phones last year). I've been holding off upgrading these devices to iOS8, but it's been out there long enough, I think i's time to ask what the 4S users think of iOS8. Stable? Sluggish? Battery life? Upgrade now or wait as long as possible, i.e., to the point where apps no longer get updated? The main advantage of upgrading would be to get them on family sharing.