One usually knows what he's getting himself into when they purchase Jet black, or Oriental blue. As long as you follow a few guidelines, Dark colors will look great. Suggestions such as :
~Washing with the washmitt in "linear" motions, not circles.
~Purchase a good orbital hand polisher and do a full detail (polish, paint cleaner, wax) twice a year
~Keep a good coat of wax on it every 3 months or every 4-5 months with Polymer-based wax.
There are two rewards with Jet Black, you actually can "see" the results of your detail (unlike white or silver) and the reflection will get you alot of "stares" and compliments. Still to this day, once a week someone asks me about my car or compliments me for the shine..something I didn't expect when I bought it.
The downsides are it gets dirty very fast (one day of rain and it looks like you haven't washed it for a month) and if you do a sloppy detail job on the finish, it'll let you know!
If you enjoy doing detail work as I do (its actually theraputic if you look at it as a hobby!) then you'll love jet black.