My opinion on stand mixers:
I own a Bosch concept mixer. There is also a Bosch Universal.
I also own a Kitchen Aid Professional 5 that has a bowl that raises
and lowers. I believe it is a 5 qt. bowl. A good size, but not the
biggest. Prior to that I had the small standard Kitchen Aid.
The Bosch can't be beat for yeast bread if you are making a recipe
with at least 6 cups of flour. It is a "quantity" mixer and does an
excellent job. Ingredients can be added easily because there is no
mixer head in the way. I do not like it for beating egg whites
because you need a large quantity to make it work. It has heavy duty
cookie beaters available for purchase. I make very few cakes and
cookies, so would be a poor source for information in that area.
The Kitchen Aide Professional 5 seems to work for about everything.
Being able to raise and lower the bowl helps tremendously in adding
ingredients without missing. I would never own the "small" Kitchen
Aid again. Even with a pouring chute (additional $) adding
ingredients is messy. You are also limited in how much bread you can
make and cannot add more than 1/2 cup flour at a time for yeast
breads or it will sling it all over. I have no experience with the
newer heavy duty stand mixers.