Originally posted by Marc Sabatella One important difference here is that upgrading from DS to any current model gives you SR, which is pretty significant, and might in itself be reason to spend your money that way rather than on a lens. For folks with a K100D, it's tougher to make call between body upgrade versus new lens.
I would have to agree, from an *istDS to either K200D or K20D is a significant gain, not only in terms of shake reduction but also HSM motors.
BUT, I would keep the *istDS for the reason I initially suggested the OP consider "downgrading" from the K100DS to an *istDS as an addition of a second body. TTL flash capability.
When I upgraded from *istD to K10D, I kept the *istD just because of that reason. I do a lot with my 300 F4 and a flash!
I'm really stuck at a cross roads, do I go from *istD and K10D to add the K20, or wait for the K30