@sgtpepper very helpful. I don't often do postproduction. I use DPP as we don't have photoshop. When I do use it I do notice the subtle improvements. Perhaps I should use it a bit more
@jennyjustfeet The main criteria are exposure, contrast, saturation and sharpness, all of which can be done in DPP with equal success. I only use PS because I got it free, and never really learnt to use DPP.