These are reliable engines which will go on forever if looked after properly, a bit corse perhaps, they provide low down torque, but as to your question if there is nothing wrong with the 1.1 I can't see the effot and expense in changing for 200CC extra displacement, in the real world there would be very little difference between the two. The 1.1 has around 53HP whereas the KA is 60HP.

The KA is EFI as well.

Martin