Size doesn't matter. (HAHA!) But seriously, I used a 40gig usb hard drive on my 730 all the time. On my 830, I just use the Bernina USB stick, but the Sansdisk Cruzer sticks all work fine too, regardless of size. I have a 16gig one, and an 8 gig one.
The information about the Bernina stick for download upgrades was correct for my machine, I don't know about transferring other jpg. files as I now use my Bernina stick & don't take any chances.
My dealer told me other usb might or might not work. You won't know till you try. My dealer was going to get one thay they will sell for alot less. Don't know yet if they have it.
I have just used my own usb stick. What I understand though is that you need to be careful of the gigs on the stick. I just use a 1 gig USB stick. Hope that helps.
Karen
I was told the same thing. But I think elsewhere in the forum folks have said they use other USB sticks. Except when transferring downloaded upgrades, I think.