Hi' A working Dualogic is a dream to drive. It's like an automatic without 'creep' , and you can over-ride it ,to change up or down a gear when it's in 'auto' . Mind you; it changes back after 10 or so seconds if it thinks you've got it wrong. You can also use it as a clutchless manual , and there again, if it thinks you've got it wrong it will over-ride you. I've been driving them for 12 years now so have had good and bad ones. When they are good they are really good , but get a bad one and they are terrible... and expensive , and nobody in the Fiat network seems to know how they work. They drop the engine revs when they change up and rev up when they change down . Magic.
BUT if you are buying second hand be very aware. They can be very expensive to fix , as garages will only change components , i.e. HP pump and reservoir, or whole actuator or ECU. Make sure you have a cast iron warranty, and look through the Forum to see the trouble that owners have before commiting. I suppose that basically you have to balance how good they can be against what they might cost if problematic.