I'm looking to buy a heavy duty stand mixer 7-10 or 12 Quart. Any tips are welcome.

I love love love my Kenwood mixer. I got a great deal back in 2002. I also have a KA mixer but I only use my Kenwood it has never let me down. Very powerful and works great for making double sized batches of fondant. My husband teases me because back in the 80's Kenwood was a huge stereo brand.

Cuisinart 7qt.

There is a big difference between getting a 7 qt to a 12qt, as there are some 7 qts that are rated for home use (and much cheaper) than the NFS rated 7-12 qts. I got the Cuisinart 7 qt and while it was a powerful machine, i still much prefer the beater rotation of the KA machines. The beater just touches the bowl much better. After talking to the KA customer service and looking at prices and value, i decided to get the KA 6000 that is not offered at costco. It is just a 6 qt, but it was also only $289 for the new motor that runs cooler and quieter than the previous 600. I almost wanted to get the KA 7qt, but didn't see the benefit for my uses for the extra $200. Not sure if that helped, especially if you are looking for a commercial machine.