My question is there a sonic difference to justify the price
If I remember correctly the KLA version goes a tad bit lower but is also heavier and more expensive.
As far as power con vs IEC, the kw181 comes with special locking IEC connectors but can take any normal IEC cable, just be wary about losing the nice provided ones or send them out with normal ones that you don't mind getting lost.
I personally own a kw181 and use others all the time and they are really a good box to have around.
If you are never going to try to fly them then the normal kw181 is probably the better buy, just be sure to get some covers for them to keep them looking like new, QSC makes one that is custom made to fit and has a pocket for the power cord.