Both models are basically suitable; the 147 (cartridge filler, "Traveller") has practical advantages on the road, because a cartridge change is faster, cleaner and less stressful than drawing up from the ink bottle. A 146 piston filler usually suffices for 25 pages and avoids carrying an ink bottle. With the nib width, many collectors advise against OBB for exams; F or M are usually more favourable under time pressure and for the legibility for examiners, although individual handwriting also matters. A pragmatic solution is the combination of a 146 with OBB for representative purposes and a 147 with F for exams, supplemented with backup writing instruments.