Originally posted by mtngal I don't mind where the AF switch is as far as using it, but it's so easy to accidentally change it when I take the camera out of a bag. If a lens doesn't focus at first, I don't panic, just change the switch.
What I find most annoying is the fact they put the live view button where the review button is on the K3, and included the delete function on it. I can't tell you how many times I've been reviewing pictures and pushed that button to go back to shooting, only to be presented with a question about deleting. For someone who's never used a dSLR before, or at least not the K3 it probably wouldn't make a difference.
The Live View / Delete button is in the same place on the K-30/50/500. I had those problems when I transitioned from a K-r to a K-30. I predicted that "metal-body" Pentax shooters would have more trouble with the K-S1's layout than "plastic-body" shooters.
The AF/MF focus switch on the K-30 was really stiff. They seem to have over-compensated with the K-S1. I will say that it is easy to check/change by touch, without taking your eye away from the viewfinder, but the old style sliding switch would have been better for the target audience, who (in most cases) would just shoot the kit lens auto/auto/auto.
Regarding the OP's missing rear IR sensor - none of the Pentax plastic bodies have a rear sensor, so far as I know. The K-30 and K-01 don't. That just doesn't seem to be a feature that they are willing to transition from the high-end to the low end.