For some reason the P9S has a special appeal for me. Maybe it's the rather unusual roller-locking system, interesting mechanism, and unusual overall appearance. More likely it's a combination of comfortable grip, reliability, and (being an HK) quality.
Anyway, it's definitely not a pistol for everyone. But I personally would seriously consider buying any P9S in mint condition, whether the 9mm or the .45, or the fixed or the adjustable sight model.