Hello Eviltwin and welcome to the boards.
I've been using a vintage machine older than I am (pre-1960) for most of the last 20-30 years. I maintain that all we need as quilters is a good strong straight stitch. However, If you wish to do your quilting with your DSM (domestic sewing machine) you do want a large throat space as well.
About a year ago now, a friend of mine gave me her replaced modern Bernina 820 "sewing computer" and it's been interesting coming into this century. My friend loves her Berninas and sewed on this one for a few years with no issues but got a new one with slightly different features. Overall, the public reception of this machine was low and there are some really negative reports, it was discontinued relatively quickly. Even with all that and used it still goes for around $3k which I consider a lot of money.
I really love the knee lever to move the presser foot up and down, but that's a feature my friend didn't use. I've grown to love the thread cutter, partial seam blocks are much more fun and I am less covered with threads. This particular machine has an extra large bobbin which is noticeable to me. The throat is huge and it is well lit, which is important to me as well. I'm enjoying have the needle down feature available by tapping the power foot or by pressing the button on the machine.
The biggest thing for me in day to day use is the automatic threader, I have vision issues and need some sort of assist. But even my cheapo low end Brother for traveling at least has an assist if not a full threader.
I've quilted down a couple of crib sized quilts using the various options of the machine, it has basically a built-in walking foot feature as well as the BSR (bernina stitch regulator) and I've just done straight lines with the regular foot. All the techniques worked well.
It is nice and easy to use. The 1/4" foot and lines work for me and there is less pull than on my cheapo Brother, feeds in and stays nice and straight. I've had no problems with it, despite the negative reviews. Hubby says it is quieter than my old vintage machine. I'm trying to use it to its best advantage but I still haven't done anything other than adjusting my straight stitch length and trying the various quilting options. Chances are extremely good that I'll never make a button hole or use 99.9% of the stitches, although I do have an idea where I'd embroider out some numbers.
Some brands are much better about interchangeable feet. I think most Brothers use feet that can snap on the proper shank, but Bernina is sort of known for having to buy all the feet for each machine each time and no portability between them.