Because I am a beginner I have a Brother CS-770. It's the best one I could afford ($200) and it has simple quilting stitches that are easy for me to perform. If you are somewhat advanced than a beginner I would suggest a different machine but for me it works great and I am happy with how it performs.

Love my Janomes. Great machines.

I would love a longer throat - just discovered there are machine called "mid-arm" - I have a Brother cs1000 I think, a cheapy to replace my beloved Kenmore from 1981 which sadly lost a main part for and could not replace :(

Any recommendations on a mid-arm are welcome.

What is your price range? What is your priority in a machine? What is the reason for an upgrade? Is it more bells an whistles or is the upgrade for a better quality stich. If the upgrade is for bells and whistles, then you can find a machine for a reasonable price. However, if quality of stich is the most important then get a good quality machine with customer support behind it. I always say, "You get what you pay for". Twenty-seven years ago, when I wanted to upgrade from a Kenmore, it came down to the stich, meaning the perfect tension, and the customer service I would receive. I bought a Bernina and still have it, and I still go to the same dealer.