I am looking for opinions on which of the two is better. I have another post on itinerary suggestions for Seville, Granada & Gibraltar & we are not thinking of doing one of the coastal cities. Can someone tell me which of the two they like better & why?

I haven't been to Cadiz, but have stayed in Marbella and found it a great location for day trips to Ronda, Nerja, the white villages, etc. However, Marbella itself, while having a nice old town and promenade along the sea and Monday market, is very touristy and expensive. I would suggest Nerja instead for a coastal city.

Cadiz is a 'working' Port City and a transportation center. Marbella is a tourist town consisting mainly of High Rise Condominiums.

Cadiz is an old city; Marbella was nothing until about 40-years ago when Torremolinos started getting too crowded.

You can catch a ferry from Cadiz to el Puerto de Santa Maria and tour the Osborne Bodegas, etc.

It all depends on what you are looking for. My vote goes to Cadiz.

I would suggest Cadiz over Marbella but it does depend on what you are looking for. Cadiz is a great base to exploe an authentic Spanish area - Sanlucar, Jerez, Seville, Conil etc. It can be touristy but the tourist are mostly Spanish. Marbella is far more built up if you prefer high rise plush hotels, there are also some reasonable places to visit but tourist will be mainly English and the atmosphere to me is not as pleasant for that reason. Cadiz is also cheaper.

we're starting in madrid, then to Seville and then to marbella/Malaga. After staying in quaint hotels in Madrid and Seville, we're indulging the spa/golfer/hedonist in us and spending the last four nights of our trip at the Westin LaQuinta. We just decided to end the trip on a 'softer' note!