I use the CITY button on my Stilo and in Punto's (as I seem to have one every month for a courtesy car), but where I live (down a narrow lane then about a 50 point turn to park), it's a great help. I also love my Stilo's parking sensors, but don't think they're necessary on these Punto's. Got one outside now actually, a 04 3dr 1.2 Active in Black. Lovely little cars!
Oh, by the way, with the Stilo: "When the vehicle speed meets or exceeds 40mph, the two systems (Power Steering and Electric Servo Assisted (CITY) Power Steering) coalesce."
(Stilo Service CD)
Stilo 1.6 Dynamic, 5dr, 2002, Crystal Green