Hello Hamzah.
To make a long story short, somehow knowing your usage, you will be happy with the KZJ. In either case, consumption will be better than with your current 3F engine. Last but not least, we welcome you to the club of coil sprung suspensions and much better seating, which will arguably make much more of a difference than your engine choice 
Need to talk about your experience with the auto lockers. Check PM.
Rao.