Yes, twice. The first one was a cheaper little machine with plastic gears. I always called it a boat anchor. I don't even remember what it was.
Then recently I bought a Sparrow because of the light weight. Took it to Bonnie Hunter's workshop where it all but died. The first day it ran fine, then the 2nd day it just would not run. It was like a magic fairy had been playing with it and screwed it up. Right now it is in a shop. I would sell it in a heartbeat.

I bought a new Pfaff Creative Vision right before I retired. Absolutely the worst machine for quilting. So much regretted it. Switched to straight stitch only vintage Singers 8 years ago (especially the 301) and have never regretted that. Sold the Pfaff for a big loss on ebay.

I picked up a free Consew industrial machine on Craigslist and then paid $100.00 to have it serviced. The tech said it's a great machine. So I hate to get rid of a great machine, but it sews way to fast for me, and I cannot regulate the speed.

Yes both new and used. Janome, Pfaff different models. Vintage Singers. Always looking for my perfect machine!