This is our standard studio scene comparison shot taken from exactly the same tripod position. Lighting: daylight simulation, >98% CRI. Crops are 100%. Ambient temperature was approximately 22°C (~72°F).
While the Nikon D300 has a slightly better per-pixel sharpness than the Pentax, the K-7 makes up for this with its higher nominal resolution. All in all there's not a huge amount between these two cameras and certainly in print it would be next to impossible to pick a clear winner, even at large output sizes. The tone curves and color response are remarkably similar as well.