Yes the PC420 features justify the 200 dollar price difference. They have a nicer easier to use threader, an automatic thread cutter, a metal frame not plastic, the ability to adjust presser foot pressure, a slightly larger harp, and I think there are a couple more features but I can't remember off the top of my head but they are definitely more high end if you are looking for your main machine, however I havve the sq9050 and it is a nice travel machine for classes as well.