Going back to the OP, gnoles point is a good one. It is probably best not to pack your best bit of outdoor clothing etc, or your best bit of any kit for that matter. Hopefully you will never have to use the bag in anger and unless money is no object it could be a bit of a waste of your best kit. The majority of what's in my bags are older clothes and bits of kit that I have spare or duplicated.
As far as I can remember I have never had to evacuate from a house either but I think that however unlikely it is you will have to use it, it is still worthwhile having one. As was mentioned in another thread, it's just another form of insurance.......and apart from all that, I enjoy it