Rabat is very different to other cities in Morocco.  It has a bustling medina with souks but they are much less tourist focussed than Fes, Marrakech or Essaouira.  The new town tends to dominate the city but with the old Kasbah des Oudaias at the mouth of the river and the part finished Tour Hassan, high on the river banks.  The new town itself is worth a visit with wide avenues and a relaxed feel. We would probably suggest just 2 or 3 nights here and it works well as a stopping point between Fes and Marrakech and the train station is right in the middle of the city.