Never been to Dubai so took the easy option and booked the city tour as an easy introduction to the city. Went around the major sights, a simple introduction to Dubai and an overview of the history and culture. Lots of time on the coach, not much chance to get off and wander around.
If you have never been to India then this is not a great way to be introduced to the country. The port itself is fairly shoddy and industrial, absolutely nothing to do at the port so if you get off the ship then you need a taxi or tuk tuk or ship tour in order to get anywhere.
Cochin is pretty interesting, we booked a taxi for 4 hours for 2 people, agreed a cost of $30 for the driver to take us to all the sights, which he did, and all with good humour and plenty of ad hoc stops when we asked to stop or go to a shop. In the end we paid $40 for a 4 hour excursion, great value.
The taxis are all aligned in the port and getting one really could not be easier. The tuk tuks are the same, but they are open to the elements, and fumes, so depends on your preference.
Was really looking forward to Batu Caves, and was pretty impressed (be warned there are 272 steps to get up there) ...BUT... we only had 1/2 hour at the caves, so 10 mins climb, 10 mins viewing and 10 mins back down and refreshment stop. This was unfortunate as you need more time there, could easily spend an hour exploring.
The trip then went to the Royal Selangor Pewter factory and gift shop (surprisingly interesting and plenty of people bought items in the shop), then lunch, then on to the KL tower and a trip up to the observation deck to get a 360 degree view of KL and take plenty of snaps. This was followed by a whistle stop visit to take snaps of the Petronas Towers and then back to the ship. A long day but again a good introduction to KL if like us you had never been there.
The last day of the cruise, so booked a city tour with an airport drop off.
Visited the Orchid Gardens (beautiful place), and the China Town/Colonial areas of the city. Really enjoyed this brief tour and would certainly go back to Singapore.
Worth pointing out that it is easy to pass a half day or so at Singapore airport, plenty to see and do, including free city tours from the airport, free movies, and rest areas that you can book to relax/shower/prepare for the flight home.