My own recent experiences with pushing exposure by 5 stops to see what happens is making me rethink my software choices. Am finding RawTherapee, which is free, is the only option for that particular task. Also has many features the other RAW converters don't. The wheels fell off when using LR4, and CameraRaw 6.7 which is a release candidate. Hopefully, it is improved before the final release.

New release of DPP includes HDR which I have been having fun playing around with. Results look quite good to me. In the 5D3 review, Bryan also spends some time covering new features in DPP. PhotoStitch, which comes on the software CD with the camera, does a creditable job with stitching. Any harsh seams created in the process are easily dealt with in PhotoShop or LightRoom. I'd favour PhotoShop for the extra capabilities it has.