As a former infantry (Army) guy, I lament your sand-machine. I'm also a family guy and have 2 kids, 10 and 7. I have an iPad2 still in use, along with 2 iPad 3's (one's a backup hand me down from grandma). I still own and use an ipad4 personally, but mostly use my work provided iPad air 2 (which is such a nice machine). I am finally at a point where I might upgrade my personal iPad and trickle the 4 down to the kids, just waiting to see what releases in late March, early April.
I'm surprised the iPads have lasted this long, but they're in good cases for the kids. The 2 and 3 are no longer updatable to iOS 10 though. Shame since they still work, but I understand the cause/reason.
As to my iMac, I updated to a iMac retina 5k, in late 2014 when they were first introduced. Love, love, love this machine. My former iMac 27" non-retina 2010 machine is the family computer now and after a power supply repair, is still in use. Can't really argue the durability of all these devices. Any other hp, or dell, would have **** itself and had some major physical failure that would have destroyed the rest of the machine by now.
What really pisses me off though is that I have no mac computer capable of running an Oculus Rift (CV1). I had to buy a PC (alienware) to run the rift. This is by itself, the most concerning aspect of Apple's refresh cycles. I think they're going to fall in to the irrelevant category for PC's if they don't get this figured out. Using a VR HMD for regular computer use is amazing, and it just really irritates me that it has to be in Windows.