I'm still using my four year old iPod Touch 5 which is slow but it works OK - Apple still sells them on the refurbished store so they're not quite obsolete even now - so, depending on what you use it for, you should get years of use out of an iPod Touch 6. As some of the other commentators on this thread have noted, you don't have to update the OS if you don't want to, I kept my iPT 5 on iOS 7 for ages and I've only recently gone to iOS 9.3.5 which slowed it down but I'm finding the newer versions of apps seem to be more stable.