If you have "full replacement value" and a reputable company, you should have no hassle. However, if you have all the normal household stuff, plus your goodies, you should add it up and make sure that you aren't bumping your contents limits. That is NOT a good thing.
I have an additional rider, just to be sure I have sufficient dollar value, plus, with my company, with the rider, I can say how much to have it insured for.
Meaning, if I don't want to pay premium to insure my 1000 antique crt to its original value, (which they probably would not hand me in cash anyway, without a fight) I can set the insured value to what I think it would cost to replace it with a projector that I would be content with. Works for me.