Well, thats difficult to say. In terms of software, you can't go wrong with the Nokia sotfware...but as I said the V3x's software has been improved (although maybe not to Nokias level). In terms of camera, Nokia's cameras aren't that great...but probably better then the Moto's. As far as reception goes, both Nokia and Motorola are known for having good phones in that department.
Summary:
Design: depends what you want, but the 3250 does that sweet twisty thing
UI: I would have to say Nokia here too
for MP3 use: Nokia
Camera: could go either way on this, I have seen both good and bad pictures from Nokias and Motorolas
Reception: more likely Nokia given its history with other phones
thats as much help as I can give