How does the Brother SE 400 differ from the SE 400? Does the SE 400 have a USB port for a thumb drive maybe?

Maybe this can answer your questions? (Your title says you want to compare SE400 with 350)
http://www.allbrands.com/products/abp14511.html

Thanks for the link. What I don't understand is by "computer connectivity" do they mean it has a thumb drive or do you have to connect to the computer by a cable? I don't want to be tied to my computer.

This sentence from their description sounds like there's no thumb drive:
"Or, you can now use USB Cable that comes with SE400USB."
Sorry.

yeah, that's what I thought. Thanks for the help though.

The SE400 is identical to the SE350 except the SE400 has a cable USB port. There are two kinds of USB ports. The SE400 does not have a thumb drive port but the kind that connects to your computer. It comes with a USB cable that connects the computer to the SE400. This is less convenient than the thumb drive because you have to use your computer for importing. Contrary to Brother's documentation, it also works with Macintoshes. You don't need Brother's software because it's all built-in to the Mac.

But it's a lot better than the SE350 with only the card slot so you need to buy extra software and a card reader/writer to import additional embroidery designs. The SE400 will also use the USB computer connection if Brother updates the software for it.

Hope this helps,
Kamala

Thank you so much Kamala for all that info. It explained it perfectly for me. I definitely don't wan to be tied to the computer, but I also want a field larger than 4 x 4 so I better keep researching.

OK, then you definitely don't want the SE400. The other one I know about is the Brother PE770. It has a USB thumb drive port and a 5" x 7" embroidery field. But it's a dedicated embroidery machine. Doesn't do sewing. I don't know anything about other brands. I'm only researching Brother right now because I love my Brother CS6000i. :)

I have been researching the PE 770 a lot and will probably go with that one. I just wanted to be sure of all the facts before I ruled out the SE 400.