No, I have not yet found a need to do lens corrections at all. What I tend to do in DPP is play with the colour saturation, brightness, contrast and shadow/highlight levels, do any cropping or rotations needed and then save the changes back to the CR2 file before saving a TIFF format copy for further processing in Photoshop CS3. I use CS3 for sharpening, fine adjustments and size reduction before saving as a JPG for upload to Flickr if the end result is up to par. I like the fact that the original image data is unchanged in the CR2 file, (which may also be true for a DNG file, I don't know), but for financial reasons I'm restricted to the tools I currently have, and I simply don't have anything that plays nice with the DNG files that cr2hdr produces. I've only had my 600D for a couple of months and didn't have any DSLR before that, so I'm still on a bit of a learning curve with it all.