Pentax's struggles to get good performance from the Samsung sensor (something Samsung itself has been unable to do—the NX cameras, which also use this sensor, lag behind 4/3 in performance) resulted in the PRIME II engine being the current best processing chain on the market in terms of IQ. When coupled with the much better-performing Sony CMOS sensors, this results in class-leading performance. The K-x was the first PRIME II/Sony CMOS camera, and its performance is stunningly good for a camera you can buy for $500.
Adam Maas
Espaço Pentax / Samsung