Personally I prefer having the gaggle of kiosks because while it's slower, there's a few advantages:
* Fewer/shorter lines to begin ordering, due to the advantage in numbers described above
* Can take my time looking through everything, even with a more complex order, without social pressure of knowing I'm hindering everyone behind me
* Foreign language options when traveling
Of course, it's probably a good idea to have at least one human employee who can at least optionally handle orders in cases where the kiosk doesn't work.