I may be among the few, but I found DxO to be too slow to be usable (I have an early slow version of Core2 Quad), and it did a horrible job of downsizing images. Apparently it does well on the RAW conversion, and you can use something else to down-scale the results. Between the speed, the price, and not being a single-program solution I chose to look elsewhere. I'd recommend a trial to see how you like it. Others seem happy with it, and it may have improved since I tried it, or your computer may be more powerful.

Adobe Camera RAW does a better job of removing noise than DPP, so Photoshop, Photoshop Elements, or Lightroom are other options to try. They've all got 30 day trials. Elements gives you limited RAW conversion options (ie: you can't paint in areas to expose differently, or isolate changes to certain colors, etc), and limited support (don't expect to use a new camera without buying a new version of Elements). Lightroom gives you lots of RAW conversion options, but pretty much no post-conversion editing options, which may make it not a single program solution. Again, I find myself in the minority preferring the RAW limitation of Elements over the editing limitations of Lightroom.

Lastly, is Corel AfterShot Pro (formerly Bibble Labs). I don't like it's default noise reduction... it leaves more a lot more chroma noise than DPP, and I already find DPP unacceptable on high-ISO shots. If you have a noise ninja registration key you can unlock better noise handling in AfterShot, but I've never seen it in action, so I can't comment on it's effectiveness.