Hi, here is my opinion
Best for me would be :
I II II IV Down Up
1 2 3 4 5 Tap
When playing live, I personnaly use only one performance for all my songs so D U don't need to be the most accessible buttons
With 5 slots + the ability to switch effects on or off, one performance is more than enough to cover a lot of grounds
If this is not possible then:
Down Up I II II IV
1 2 3 4 5 Tap
(anyways I guess there will be arrows on the buttons so D U or U D is not a big deal to me)
I don't use the tap button, so like someone said it would be great to have another use for it
Finally my performances are not ordered by song, but by amp (different versions of the same amp, clean crunch lead, etc...), so again if I were to switch performance (and amp) during a set , I would not necessarily go straight to the first slot (cf Up button above slot 1)
Finally the most awesomest thing would be to have colored leds to see the type of effects in each performance
Anyways I'm glad to see things are moving
Thanks Kemper team