Is 325 watts enough when other mixers quote more?
Wattage tells you how much power the motor draws, not how well the mixer turns a heavy dough, so it is a poor way to compare mixers on its own. How it behaves matters more: the Artisan handles cold butter, dense doughs and sticky mixtures without slowing, and it is solid enough not to rock while the dough hook works. KitchenAid builds it with metal construction, which is also why it weighs 11 kg.
Is it any good for bread?
For everyday bread doughs, yes, and it keeps going on dense doughs without slowing. Knead on a low speed, keep an eye on the dough hook because dough can climb it, and stop to push it back down if it does. If you bake large quantities of heavy bread every week, a bigger mixer designed for that load may suit you better than a 5 quart tilt-head.
Is it worth the money?
For regular bakers, yes, and the case centres on how easy and sturdy it is. The case is strongest if you will use it often and may add attachments later. If you bake a few times a year, a hand mixer does many of the same jobs for much less and takes up far less space.
Do I need the attachments to justify the price?
No, but they add a lot. The mixer alone is sturdy and easy to use, and those are its biggest strengths. The hub on the front runs over 10 optional attachments, from food grinders to pasta makers, so you can add jobs over time rather than buying separate appliances. If you have no interest in attachments, you are paying for a hub you will not use, so weigh the mixer on its mixing alone.
Why does the head tilt back?
For access. Tilting the head lifts the beater clear of the bowl, giving open room to add ingredients, scrape down or swap beaters, which on a machine this heavy is much easier than working around a fixed head. Lower it by hand, though, because it can drop hard if you let go.
Is five quarts big enough?
For home baking, comfortably. KitchenAid sizes the 5 quart bowl for 9 dozen cookies in a single batch with the flat beater, and it is deep enough that ingredients stay in the bowl. It covers cakes, cookies, whipped cream, icing and everyday bread doughs. Anyone baking in bulk every day would be better served by a larger machine.