Originally posted by reeftool If your K100D is working and fully functioning, I think you would do better saving a little longer and picking up a used or reconditioned K5. Not that the K20D isn't a decent camera. I have a K10D that I still use and it's my go to outside winter camera because, as others have mentioned, you can use it easier with gloves. (The K20D body is nearly the same) Since you live in Texas, I doubt you will be seeing below zero temperatures so the gloves issue isn't really worth mentioning. Being fair to the K5, I mostly need to take the gloves off to turn the mode dial because it has a lock button and if you aren't changing modes often then it really isn't an issue. I have outfitted my K10D with a Katz Eye screen and I shoot with manual glass a lot. All that said, the K5 is much more camera in regards to resolution, high ISO shooting in low light, larger and much better rear LCD, (I could go on). My K10D is my backup and second camera. My K5 is much better all around.
My K20D is still worth keeping, so I guess my answer would be that it is still worth buying. I will not let that camera go until it dies. And if it ever quits, I would replace it. I love the sensor on this camera, and it is such a reliable performer (and sturdy!) I love to pick it up and use it. I use it mostly for indoor work now, although I would have no hesitation in taking it outside in any weather. You can use a flash with it with no problems.
The K20D will put a really big smiley face on you once you put better quality glass on it. The camera is just a mount, really, and the glass is what counts.
EDIT: I have to confess though that I haven't met a camera that I didn't like. I have two Pentaxes and two Canons and I am fully satisfied with all of them. As long as you put fine quality lenses on the front, any of them will perform beautifully. I guess I am just very promiscuous.