I too have an 830 and has been back to the dealer numerous times in the past year (I've had it for a year!). One of the issues is the thread 'alarm' and I've been told if a little fiber of thread gets caught (which is unseen to my eye) that's what happens. They told me to turn the alarm off and sew until it's convenient for me to drop off my machine! Last week a 'piece' of something flew out at me and I had to take it back (I think it was part of a spring) and I asked the dealer if I was sewing too much (because basically I truly enjoy sewing with it) and he said 'no'. When I returned to get it after it had been serviced, he offered to trade me to the LE830 for $1995...I'm sitting on the fence as I just got it last year!!! However I have wondered I bought it and it had been used 6 months prior to my buying it! I feel fortunate to have the Bernina dealer that I do as he always tries to accommodate my schedule with servicing (as I live an hour away) and now he's given me this offer...still thinking but he told me to sew to my heart's content and see if it works ok for longer than a month!!! That's my experience so I'd say I'm 75% satisfied with my machine!