I was told Aurifil and it seems to like that just fine. I'm trying using So Fine by superior as a bottom thread and it is pretty happy with that too. When the sensor went out it was noticeable, I was sewing down binding and could only go an inch at a time without hitting the reset button.
I've been sewing on a vintage machine for most of the last 30 years and was gifted with this. I had very little modern machine use other than my portable Brother(s), and do/did not have a favorite brand. I decided that I could either use it the same way as the vintage machine; i.e., pretty much straight stitch only or I could see what this century has brought
I really like the ability to stop with needle up/down with the foot pedal. I have vision issues and don't see the buttons well but I can tap my foot. I really like the cut thread, didn't expect that! (while I have those vision issues, cut thread is in a handy easily remembered position) Apparently some of the things I didn't like dealing with like partial seams was partly the thread. I also use the knee foot up/down control -- my friend never used that but I really like it.
Most of the time the thread needle function works perfectly -- if it doesn't it is usually a good idea to change/reset the needle.
I love the large throat and the bright lighting. I would like to get a table where I could set it table height for quilting, but I'm ok piecing with it on top, but I'm on the lookout for a table big and sturdy enough to hold it.
The integrated walking foot feature is nice. So is the BSR (Bernina Stitch Regulator). I feel I could quilt down a queen sized project satisfactorily but I just don't want to! I have done several crib-twin sized projects, I really like having the Serpentine stitch available for quilting down.
It has an extra large bobbin which I can appreciate (especially loaded with the So Fine it goes forever), but I'm annoyed that it is a proprietary bobbin and I can't buy pre-wounds. Especially if I had the embroidery options I'd want pre-wounds.
I usually don't do much with fancy stitches but because the hubby asked I repeat embroidered his name on the bottom of his bowling towel. I've also tried some of the fancy stitches for potential projects.