Great question, I shoot and work in post as an Online Editor / Colorist. I've been a big fan of the pro res coded for a while ever since the FCP 7 days. However, now that I work primarily in Avid/Davinci and have been exposed to Avid DNxHD, my opinion has changed.
I know swear by the Avid DNXHD Codec. The reason being is that it's completely free to anyone via Avid's website, and in the tests I've done it produces a less "processed" final image when exporting.
I worked on a feature a year or so back where we had to have some intricate, heavily roto'd VFX shots. All footage was 23.98.
When we had the shots delivered back to us, we had them mastered in Pro Res and Avid DNxHD QT files, and the Avid DNxHD image was the cleanest and least processed looking. The pro res all had a hint more saturation, and had noticeably higher contrast compared to the Avid DNxHD 145 image.
File size wise, they are both managable to handle even with less powerful edit bays and slower storage systems. I would also argue that Avid DNxHD can be created in plethora of different color depth/quality grades and compared to the Apple Pro Res options.
All in all though, it's about what works best for your project.