I have done this many times. It makes life much easier. You don't have to worry about fitting things in your luggage. We still laugh about the year my nephew saved his money to buy the monorail and many of the buildings. Because we could not find all the pieces in one store, we ended up shipping four orders. They arrived via UPS on four consecutive days. On the last day, the UPS guy asked if we had left anything in Disney World. I said, "Nope. You have just delivered the EPCOT ball."
Some purchases require that you ship them home - my nephew's swords from China.
I always send home fragile items. If they break in transit, Disney replaces them.
We were home only a day or two when the items arrived. So the delivery time is probably 7 - 10 days.