Bought a K-x this afternoon (black) with the kit SMC PENTAX-DA L 3.5-5.6 18-55mm AL. Price was AUD $799 from Officeworks.
Loaded the batteries, and went out to test it.
Impressions of the body are positive - quite solid and sturdy, even though it is noticeably lighter than my K200D. However the grip feels very different from my K200D, and the battery cover feels rather flimsy/wiggly, but it seems to hold together OK. The DA L lens also has just a plastic mount.
In use however the K-x has killed off completely my Nikon D90 envy. It really works well at high ISO's and standard ISO too, and the video (which I was prepared to ignore as unimportant) is actually really cool, especially if you are into live music like I am.
Anyway, I didn't read the manual at all but just went straight out shooting to the first day of the Lismore North Coast National agricultural show.
The following photos are the result. All were taken with the kit lens, which actually performed extremely impressively for a $50 lens.
The K-x has the goods all the way up to 6400 ISO. All the photos below were taken using available light only and with the K-x kit lens. All are just resized JPG's straight out of camera. I think some in-camera NR was applied to photos > 1600 ISO, but it is very subtle.
First stop was Tommy's pub (3200 ISO):
Then onto the Show. Here is a 6400 ISO chicken. (The light in the poulty hall was really dim):
Fun on the rides at 200 ISO
More fun on the rides at 200 ISO
Bumper cars at 200 ISO. (The kit lens is really doing quite well).
Then check out some paintings at 3200 ISO.
Time for a coffee at 6400 ISO.
Then catch the gig by Melbourne band The Junes (at 6400 ISO):
The Junes know how to have a great time on stage (at 6400 ISO):
In short, the K-x is a very commendable little cam. The sensor is exceptional and the kit lens isn't a slouch either. In terms of price/performance, I think it's a bargain.
FYI.
(PS: Let us know if the images don't display OK).