Brett Baker's comments on KA stand mixers are consistent with my
experience also. A mixer should be able to handle whatever amount of
dough fits into it. I think the new KA's are intended primarily for
mixing cake batters. There aren't enough bread bakers out there to
warrant the extra cost of bigger motors and metal gears.
One mixer not mentioned in Mike's discussion is my Viking stand
mixer. I've had it for about 4 years and it is tough as nails. I
posted a bagel recipe here several months ago that uses extra gluten
added to the flour. I mix and knead a 6 cup batch of that very stiff
bagel dough in the Viking and it just plows right through it. The
only drawback is that it is a screamer! You won't be doing any covert
baking with a Viking.
Werner