Actually even the very first Pentax dSLR -- the *istD is still a very capable camera even comparing with the most latest dSLR cameras. It still takes great photos.
All dSLR cameras (be it a Pentax or non-Pentax) on the market or phased out ones are good enough for most amateurs. Some cameras are better than the others in some aspects, but IQ wise, they are all very good imo, especially at lower ISO. All these cameras are capapble of taking great photos when used wisely, but they take lousy photos too, even used by a pro. It's just a pro might be able to take more good photos than bad ones, while for us amateurs, we'd take more lousy ones than keepers.
Back to the topic, the K100D is still a great camera. I have both K10D and K100D, but the K100D is my daily camera due to its smaller size and lighter weight. IQ wise, I'm very happy with the JPG output from this camera. And I don't see any reason buying the K100D Super over the K100D at all if you are not planning to buy any SDM len in the near future. If you plan to have some SDM lenses after 2 years, well, you can get a K10D then at the price of a K100D now
Besides, you can still use a SDM lens on K100D, it's just you won't have the smooth quiet AF, but the lens still does AF fine
Cheers and happy shooting!