I agree with what Robyn said here..
I've gotten snakes every way you could think of from hand delivered to Delta Dash and it always comes down to the shipper's ability to properly package and schedule the animals trip. That's not to say that stuff doesn't happen but the chances can be greatly reduced by good shipping methods..
I've got maybe 90 out of the 100+ snakes in the collection shipped to me form every where from NH to NA and never had a problem, but then again the shippers were top notch and experienced..