Most of the time, reincs will not have your gear, relics or all your rubies. So a morpher (from AH or a core) is better if you plan to change class and don't want to lose your progress, on gear or on quests. It will be the same exact char, just with a different class.
A permanent morpher (to switch between two classes at will) is very useful to be more flexible in raids/parties/domi.
If you just want to experiment a class or have fun with it without playing it seriously, reinc is the way to go.