i send quilts all over the country on a regular basis- i use post office flat rate priority boxes/packages. it is cost effective and they arrive in 3 days. it is an additional 70 cents to add delivery confirmation which i also find very cost effective.
for customer quilts i always add insurance- if you insure for over $200 the delivery confirmation is included-so not an extra charge. i think it's $1.70 for the insurance.
trying to keep the post office in business :)