I have used a place called 'The Box Stop' and they have dedicated guitar boxes. UPS often won't ship instruments unless they're double-boxed (as was my experience just yesterday with a '79 International Series Strat in Maui Blue).
So yes, many packing places will do an astounding job on the packing. Of course, I've also just stuffed the cases into their original shipping boxes (Rics included) and shipped them that way.
Remember to secure the case candy and feel free to add some extra bubble wrap or foam inside the case if it eases your mind or reduces vibration.
I've had them pack for me before--I do some "prep" packing, usually involving thin foam sheets or small bubble wrap inside the case, but my experience in the places I've used is they overwrap. Downside is they usually bang you pretty hard for the packing.
If I have a suitable guitar box, I'll pack it myself.
In Canada, UPS won't insure for damage if they don't pack it for you, which will cost about $100-150. This increases the ship volumetric weight as well.