Hi Mother Hen to 6!
I have received quite a few shipments of hatching eggs over the years and have pretty terrible luck. If you want unusual breeds, though, you may be stuck with having to purchase them from remote breeders. I plan for 0% hatch rate to avoid disappointment.
Off the top of my head, my hatch successes on flown in eggs were 0/12, 2/29, 2/14, 1/12, 0/14, 2/12--I know there have been more, but you get the idea. THe distance didn't seem to matter, eggs were from as far away as both coasts (may 2K miles) and from a neighboring state (800 miles). From this group I have hatched 7/93 eggs or overall 7.5%
--At first I thought it was me (incubator issues) but then I decided to put eggs from my own flock in and I have 100% of fertile eggs hatch eliminating me as the problem.
--I also thought that it may be the altitude as I am at ~5,000 feet and most eggs were from near sea level. I talked to the Poultry Vet at the local University and she said they receive many, many eggs frequently from the east coast (FedEx overnight) and have excellent hatch rates. So altitude/plane ride may not be a huge factor
-I believe packaging plays a role. I think that the tighter the eggs are locked in, the worse by a little my hatch rate. The shells are not cracked, but the embryos may get damaged as the shock of deceleration when the package hits the bin from the drop off the conveyor. The vet I referred to said her eggs come in stacked flats packed with sawdust to take up space between the eggs, that unit is wrapped together and boxed and that box is placed in another box that is nestled in insulation material. I have received eggs individually sealed in bubble wrap both in and out of a second box, wrapped in tubes of bubble wrap and sent in a Coleman egg carrier (4 were smashed but I did get one to hatch that was small and was able to shift in the carrier.
-One shipment was delayed during a heat waved in CA and probably sat for 2 days in 90 degree heat before making the plane ride--I got 2.
-I personally have not seen a correlation between egg size and hatchability.
I just hatched out eggs I drove myself about 850 miles (they came in cartons so I packed insulation around the eggs to cushion them and placed into a cooler--my car is climate controlled but has a bad shimmy), let them rest 36 hours at room temp before setting then did not turn on the turner for 24 hours. Out of 18 eggs set, I got 2 infertile eggs and 3 late quitters for an overall hatch of 72% but 81% if you exclude the infertile eggs. Both eggs from my own flock hatched.
I have decided that in the future I will cough up the money to try express shipping as I am ordering expensive eggs and even if I hatch a few eggs more, the shipping costs will be worth it as the per chick hatched cost will be the same... but I will have more chicks overall from the shipment to grow out.
The only eggs I've ever had any luck with shipped from CA to CO were White Bresse, everything else has been nearly a complete fail. The Bresse did so well I'm about to try them again to see if it was a fluke 
