I’ve been doing it for nearly thirty years, it’s just a habit that’s treated me well. I send my gear into Nikon for service once a year. I time the sending of my gear so I have in the locker what I need for the next few weeks. This means that about half goes in for clean, lube and adjustment every six months. This is not for repair, this is to clean six months of “work” off, tighten loose screws and just simply, well, a massage treatment for gear I depend on. Like I said, been doing this forever and in all those years, my gear has not let me down. In this case, I’m sending in just my main D5 body as it’s not been in for a year. Yikes!