I used to have two until my granddaughter, who would never go near a sewing machine, sat down and starting sewing on one of them. She has finished her first quit and I wanted to show her how to quit it on my 201 but she chose to tie it off. The big machines must scare her. So needless to say, I'm losing one of my twins to my granddaughter.
I've never sewn on anything newer than a 401 so I can't speak to the speed but the twins do a great job piecing for me. I do have them in a FW table which may be a help.