Originally posted by Rondec I think we need to be honest and say that the biggest upgrade from the K7 to K5 was the fact that Pentax actually got a current generation sensor from Sony (unusual since there seemed to be embargos on them in the past). Auto focus was the same (or worse in some lighting situations), frame rate increased incrementally. Otherwise, I haven't seen a "game changing camera" from Pentax since the K10. Everything else has been about small improvements in specs -- usually pretty far off the current specs available from Canon/Nikon.
I wouldn't make that assessment. I "upgraded" from a K10D to a K-7. I was so disappointed I nearly sold the system. The K-7 image quality is *vastly* inferior to the K10D at low ISOs. The auto focus was disappointingly unchanged from the K10D and less accurate (in really strange and unpredictable ways), and I couldn't get a clear shot at certain shutter speeds because of the much discussed mirror slap issue. A warranty service fixed none of these issues.
The K-5 has addressed all these issues. Low ISO is almost as good as the K10D, the auto focus is responsive and positive, and the mirror slap blur is gone. It was a major upgrade from the K-7, and the enthusiastic reviews of the K-5 is why I took a chance on upgrading. It's the first Pentax camera I can recommend to people without caveats. Want a camera? Buy a K-5, you'll be happy. That's not something I'd say of its predecessors. K10D had great image quality but lackluster auto focus, poor color balance, and a common back-focus problem. The K-7 has no redeeming qualities of any kind as far as I'm concerned.