Just to complement what has already been said, the traffic can be annoying and in certain areas parking is challenging. The driving is generally better than other regional areas (especially when you compare to Saudi (worst), Qatar and Kuwait (next tier)). I am always in favor of public transit, and the metro is quite useful(and has bus or other options for special destinations from the metro stop), although it is not 24 hours. So depending on where you are planning to go and when, I would advise either public transit complemented by taxis or renting (as compared to taxis exclusively).