I have been considering doing a playthrough of a number of my favorite Ultimas (specifically 5, 6, and 7), and remembered how in Ultimas 4 & 5 (and onward?) allowed importing your character from the previous game. Does anyone know offhand if this is still possible via the GOG/DOSBox versions, and if it was just 4 -> 5 -> 6? I didnt think U7 Part 1 & 2 had it, which I would think would have made the most sense of when to do it :)

You can only import in the order of 4 -> 5 -> 6, but you can't import your character from 6 into 7 and you can't import a character from 4 into 6. Officially the import feature for the secod trilogy doesn't work with the GoG version, but in reality it does. At least for 4 -> 5, I haven't gotten to 6 yet. you might have to run a small tool to patch up your save file, at least I had:
http://ultimacodex.com/2013/06/ultima-v-character-transfer-fix-for-the-gog-version/
(not usre if that is the same tool I used, I can't find the old link)

However, there is not much point in importing your Ultima 4 character to 5, all it does is give you some extra experiece, which you can just as well give yourself with the savegame editor. It's still a nice touch though.