Second, to the extent that people/customers will type the name of the business right into the nav bar (i.e., direct navigation), even if to 'search' for the business, then the vast majority will add the .com at the end, and not necessaryily try .net if .com doesn't work.

If however you expect the majority of your traffic to be from the search engines, the .net is not very significant, except for the extent to which it affects click through rates (if at all).

Personally, especially if using a domain that reflects exactly the name of the business, or the first word or two words of the business, then if I were in a position to wait, personally, I'd do it, and try to get the .com.

My 2 cents anyway.

But I'd not wait; I'd find an alternative .com

The five months could be forever, and the domain could be used to harm, blackmail or otherwise damage a .net (I've seen a porn site set up specifically to blackmail a .net owner).

By all means keep the original name as Plan A; but until you can achieve that, you need a plan B. Or deep pockets or a good lawyer!

Shoulda added that point.

I HATE being in poor negotiating positions, and/or, not having a back up plan.