We had 2 of them. Lovely little cars with a surprising amount of room. Both were written off in accidents, no one badly hurt, and neither our fault.
The second, a 1.3L, was exactly like you said, turn on the A/C with 2 people in the car and you could feel it slow down. The first one was a 1.5L and a lot nippier and the A/C seemed to have no effect. Looking back now they seem very expensive and show how prices have dropped for small cars.