I have a Husqvarna Designer 1. When I bought it, I was not into quilting and it was easier for me to use than the Bernina. I was into garment sewing and embroidery. Now, I am more into quilting.
I would not like to be without the needle up/down feature or the sensor foot pivot. I can free motion on the D1, but it does not have the stitch regulator that is available with Bernina. The stitch regulator comes built in with the Bernina 830 and as an attachment with the 440QE. I would really like that feature. And I like the top loading bobbin, but Bernina 830 looks easy to load. Nor could I do without the needle threader.
I don't use all the special stitches available. I have used some of them on children's clothes and a few on quilts.
Were I in the market for a new machine I would probably want the Bernina 830, but it is very expensive. I especially like the 12 inch space to the right of the needle. That makes a large space of quilting, free motion and thread painting. Wish I could afford it in addition to my D1.
Do test drive every one you might be interested in purchasing. Go back several times to try them out. After all, this is a big purchase and you want to be happy. I worked in a Viking Gallery and many customers bought without comparison shopping and were not happy with their purchase. Some returned the machine and upgraded or just got their money back. The ones that were the happiest with their new machines were the ones who did the most test driving. Don't let the sales persons hinder you from testing.
Good luck and have lots of fun doing the test driving.