I found a great KitchenAid mixer comparison chart:
https://mixitbakeit.com/compare-kitchen-aid-stand-mixers/
Lists all the main features such as gear type, wattage, HP, bowl size, warranty.
Of note: The 5 qt and 6 qt models have a 1 year warranty. The 7 qt model has a 5 year warranty. The commercial 8 qt model has a 2 year warranty.