I bought the 830 about a year ago and love it! I do still reach for the presser foot lever now and then. I never need leaders/enders - it never eats my fabric. That's one of my favorite things about this machine.
I do use the B foot more than the A foot because it's easier to pull the thread to the back with that one due to the tab on the A foot. I didn't like the R foot and didn't have luck with the spring foot from my old Viking, so the dealer had me try the 4125417 spring foot and I was so pleased, she gave it to me. I haven't had a problem since! When I remember, I set it to C when I'm quilting, but often forget.
I rarely touch the tension, change the needle with each new quilt, clean the bobbin case at least with every bobbin change, if not more. I run the bobbins until they are empty most times and don't have problems with the bobbins. I do wish they wound a little neater. I must admit, I have not wound the bobbin while the machine was still threaded. The dealer said it's better, puts more tension on it, but I still haven't tried it. I must fish out the book and look it up.
I wish you could set it to stay at 1/4 so that when you shut it off, it would come back to that. But I taped a post-it to the bed of the machine to remind me. :)