I received the K-5 kit with its 18-55 all times, I went through a Nikon D40 and Pentax K200D. I enjoy with this device, I rarely caught out. I went to test it in conditions of very low light at Notre Dame de Paris indoors on a snowy day, the AutoFocus not betrayed me at any time, even in some cases where I can not even make out the scene through the viewfinder, it was my biggest complaint to Pentax, they shot well corrected. The second strong point is its image quality, rated best in class against the D7000 and D60 on DxOMark, the increasing iso is fantastic! I highly recommend using the mode 80 iso (that are not found elsewhere in its price range), which provides images of exceptional quality for an APS-C DSLR with a dynamic image which allows a HDR (high dynamic range) with a single shot. We must shoot in RAW format to enjoy all comfort, and developing his photos himself, nothing to do with a limitation of the box, but the jpg images are coded on 8 bits of information, against 14 for the raw, as in competition. The construction is exemplary, one can find here and the videos on the net showing the quality of the all-time protection, or K5 came under the shower and work without any problems.
If you are ready to get out of the shackles "Canikon", have fun with that K5 is a small bomb that has nothing to envy of its competitors, on the contrary. I suggest you have a look at the picture are forums or posted pictures of the K5, to see what was in the belly! And enjoy the park Pentax optics, new or old, one of the other big advantage of this brand is to keep a compatibility with all his bayonet objectives products since the 70s, it even keeps the automation if the goal is provided (metering, iris control, autofocus ...) Pentax is an innovative brand since the 50s, they invented the reflex viewfinder pentaprism by that is still used today, especially not see them as a player in the third area, dépotent their devices, and want to stand out from the competition with functionality that only found in much more expensive devices.