I really love my Bernina 590! I've had it for about 4 years.
I was a sewing machine tech for 8 years, and came to understand what any machine needs. If you hold the thread tails every time you start sewing (like we all learned in Jr. High sewing class), that will eliminate a lot of your problems. Especially with the newer Berninas, and especially when you use the embroidery feature.
There's a work-around for getting your 1/4" seam on the wide feed dogs. But it's like any machine, everyone finds their 1/4" in a different place. I like to guide the fabric just inside the feed dog hole. Some like to use the edge of the presser foot. Others like to guide the edge along a line on the needle plate. You will be more successful with your 1/4" seam when you employ both feed dogs. So use those bells and whistles to make it work for you. I use the clear #34D foot and move the needle position over 3 bumps.
I love the lighting, the jumbo bobbin, the "hover" feature, and all of the other programmable options.
Bernina really messed up for a few years, but I think they've got themselves back together.