Originally posted by sharathk i'd go with the K20D unless k-x has better IQ or AF speed.
reasons-
K-x doesn't have top lcd, no front e-dial, which you'll find very helpful once you get used to it. on K20D you can change ISO, shutter, aperture, metering etc all with dedicated buttons, which k-x doesn't seem to have.
K20D is weather sealed, K-x is not.
i don't care about video.
All of the above what sharathk said is true.Also the K-x has a faster fps which is around 4.7,compared to K20's 3.0,which is good if your doing sequence shots.If you like AA batteries,then the K-x is for you.If the K20 is good condition,then for me I would buy that because of LCD screen,Weather seals etc.But if you can't decide,then take them both for a test run if possible.That's the only way your going to truly know what's best for you.