The 300 is an older model. The 350 replaced it at least two years ago. I have had my 300 about five years now. I love having an embroidery machine, but I have had a lot of bobbin trouble with my 300. In the shop 4-5 times a year. Also, the 300 uses a card to import designs from your computer to our embroidery machine, while the 350 uses a USB port to pull designs directly from your computer, which is much easier. Hope this helps.