Everybody's best protection depends on their particular use. So as always the answer is it depends for each of us. But reeeeally - does bolting a metal cage to a radio protect it from much? If I whack a radio with a rock, a metal cage may protect the case, but that case will transfer most of the impact to the radio, the display, what's mounted inside. If you look at the standard that most rugged portable commercial stuff is built to - Mil STD 810 G with some extra letters maybe, they emphasize survival with things like drop tests, as well as testing other threats like vibration, dust water, temp, humidity......... Considered in that context, Icom didn't do such a bad job with the backpack. And when the radio's not in use a Pelican-style case is great. But if you look at things expected to survive rough use, you find things like shock-absorbing mountings like Sorbothane, possibly a plastic out case that absorbs a lot of impact without transferring it to the radio, etc. There are alot of better solutions for most hazards than a metal case bolted to the radio, IMHO. I wish someone would make one smaller than the Icon backpack.
They've already made the mistake of creating a 703/706 series that works and doesn't break for decades. You won't earn that much ...