Planetary mixers are very versatile and lend themselves to a variety of preparation tasks from whipping cream and mashing potatoes to kneading lighter doughs. Most, all kitchens will need one.
The maximum kneading capacity is not the same as the bowl capacity. The maximum kneading capacity is for the dough, it’s a measure of the working ability of the mixer.
A machine with a good reliable motor and gears will mean the maximum kneading capacity will be bigger. The low speed is for the Dough hook, the middle speed is for the mixing paddle for mashing potatoes, etc and the high speed is for the Whisk.