The argument against oil and wax finishes is that they get dull over time and wear off. I've done a lot of pens with all kinds of finishes (CA, wax, BLO, lacquer), and my preference now is either BLO for super hard woods (like African Blackwood) or urushi. CA is OK if you are going for a moderately durable glossy look, but I think CA pens that are actually used a lot tend to get banged up, scratched, etc., and are not easy to restore at that point (correct me if I'm wrong on this point). Wax and oil finishes are very simple to touch up if needed, and I like the natural appearance of a wax or oil finished piece of wood. Urushi is probably the most durable finish. If you are doing a Fuki Urushi finish (multiple extremely thin layers of translucent Japanese lacquer), the deep warm semi-matte finish is the best (just my personal preference). The downsides of urushi are numerous however - it's not east to get (you have to import from Japan generally), it's expensive, it requires a furo (humidified box) for curing, it takes a long time (usually 24 hours between coats), coloration is quite hard to control if you are going for anything other than a natural translucent finish, and it causes a very nasty rash if it comes in contact with your skin (don't ask me how I know).