Actually they arent the same. Asda setup is on proper Fuji processing and printing machines, commercial ones - the kodak kiosks are nothing more than a pc with a printer attached in a fancy stand!
The difference in quality is massive and personally, i would never print any of my portrait, wedding or other commercial pics on the kodak self-serve machines, but its all down to personal preference. The Fuji machines suit my colour tones/work very well.
As for home printers, you are right, they are viable however as you said shops are quicker, easier and most definatly better quality so its a bi of false economy owning a home "photo" printer - unless its dye-sublimation, but thats a different matter all together