I usually just ssh and copy them over on winscp the only benefit to the USB stick may be if you don’t have a network connection or sometimes it will copy over faster than the network depending on your hardware of course. One thing that you’ll need to take note of are which ROMs are parents and which are clones. If you get clones without parents (like pacman is really a clone of Puckman) they’ll give you a missing ROM error. You can see the compatibility lists on aforementioned managing ROMs wiki page and they list which ROMs need which parents. Usually I’ll just build the whole romset and copy the whole thing over or I’ll build a merged set which puts all the clones in the parent folder (its not the most efficient on space though.) Sometimes rebuilding won’t work regardless (like in my case donkey Kong) and I just had to find an older romset for some of those or at least individual ROMs.
Reply To: Problems with MAME due to romset version. Would romcenter or clrmamepro fix it?