Top 3 gears of manual are quite close in ratio, so prepare to do a lot of shifting. Corresponding ratios of auto are more widely spaced as well as being (mostly) taller overall. Overall ratios of lowest 3 gears are about the same, so expect lower acceleration times to 100km/h for the auto, as is usual.
Cerato (Forte) transmissions and ratios are similar, and the manual is a little quicker to 100km/h as reported in various tests. However, you would need to punish the clutch to achieve this.
I'm very happy with the performance of KIA 6-speed autos. The car spends a lot of its time in 5th and 6th and returns good fuel economy because of the tall gearing. I think I would find rowing the manual along a bit of a chore, particlarly if you needed to change gears frequently just to maintain speed in everyday driving.
More powerful cars with 6-speed transmissions are less demanding. Adequate torque means that you can drive most places in 5th gear and only change gears when you want to really stir it along.
Last edited by Wry 'Cuda; 12-26-2012 at 02:55 PM.