This is what i found out today (I also posted this in another thread about the switching lag) :
Some short news :
Just for fun I switched the cab on my clean profile to the same cab I am
using with my high gain profile and it felt like the switching lag was
reduced to a 'size' where i could switch the rigs almost flawlessly with
a little practice. Great so far.
But :
After that I programmed a midi track in REAPER to change the KPAs rigs
for my bands' live-setup (just switching from high gain to clean and
back) and after playing along to that backing track while recording the
KPAs output i found out that the lag seems to be inconsistent ranging
from around 100 ms (which is what Kemper told me is somewhat normal and
what was taking into consideration by me when programming the above
mentioned Midi track) to way more.
Conclusion : I will be bringing back my KPA to the store where i bought
it and check one of the KPAs they have in stock with a BEHRINGER
Floorboard and my NOBELS board to see if the lag is also apparent in the
other units. Hopefully its not and i can drive home with a fully
working amp. We'll see...