Darin -
You're right that the root ball MUST remain intact! Fractured root masses are as much a problem as that other problem you identified earlier, Darin, the breakage from "whiplash" (which I did not specifically address, since you had covered it).
Regarding the baskets -- I only have some anecdotal evidence - no scientific study. Not all baskets rust away within two years. I have seen some made of galvanized material (obviously meant to avoid rusting) which have remained perdurable/indissoluable/tough enough to be causing girdling ten years after planting.
I hope Tree MD is still following this thread. The answer to his question is probably product-specific. Ask about or inspect the wire. If rustable, good; if not, adapt your planting methods. At any rate, maintain the integrity of the root ball. If wire left in place, I would suggest monitoring to be sure it's not a problem. (But now just who is going to pay for that? And, do we dig it up if it doesn't rust well?? And, how do we keep the newly-grown roots intact???) So many variables!
That, too, is why we search for answers on such a Forum as this. There are seldom black-n-white answers, but we learn some of the questions which our peers would ask that helps us give our client the best job available for the $$$ they put to their project.
That's my 2 cents.
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