I think you need to 1st decide what you actually want to do with the machine such as; Do you want to make clothes, do you want to do decorative stitching, do you want to embroidery, do you want to do heavy items like hem jeans, do you want to do just quilt peicing, do you want to use a walking foot, do you want to do free motion quilting, do you want to quilt with very fine thread, do you want to quilt with one color of thread on the top and a different color in the bobbin? Some machines will give you better results than others. For instance, the auto tension is great if you are sewing with different weights of fabric but isn't very good if you want to free motion quilt with fine thread or two different colors. If you want to make some of the heavier quilts you may want more power than most domestic multi purpose machines have, especially if you want to do walking foot quilting, you can actually burn up the motor in your machine or you will not get good results with the walking foot, usually very tiny tight stitches and uneven fabric feeding which you do not want in a quilt and also they are a nightmare if you have to pick them out. On the other hand if you want to mainly do general sewing and want zigzag stitching then some quilting machines would have way more power than you need and most are straight stitch only. I have 2 Babylock machines which I use for general sewing and machine embroidery and I also have the Juki TL98Q that I use for quilting, I love the compensating foot for peicing, especially chain peicing and construction, the power and speed makes many jobs go much faster. The pressor foot preasure is very easy to adjust as are the needle tension and bobbin tension so you can use different weights of thread and 2 color quilting. Sorry for such a long post, I just wanted to give a little more to think about before you make your final decision.
Good luck on your machine shopping.
Hugs, Gail in Utah