Why use 3 year old obsolete tech? I will likely have moved on by that time and if it is still ticking, then bonus. I haven't held onto a cell phone for more than three years lately, why would I do the same for what is basically a low-tech cell phone on a stick? Based on detector price trajectories anyway (Vanquish, Simplex), the cost of a replacement control head would likely not be outrageous or they will just force their users to seek out cheaper, more capable machines. We'll see. My main concern with these is the durability of the control pad and side switches.
Just gotta face the music, the days of discrete accessible component circuit boards and solder repairs is over. People want an environmentally robust enclosure, that means either removeable seals (risky) or a completely sealed housing. You can forget about repairability at that point.