I have just finished Steve's excellent image stacking tutorial. At the end of this week, I am off to the Scottish Highlands, for a week of landscape photography and itching to put the theory into practice I have no experience of using the software but from Steve's information, I am favouring Zerene. My question is, what is the difference between the personal edition and the prosumer? Is the "Personal" version good for most scenarios, or will I be left wishing I had spent double on the prosumer. I realise that it can be upgraded at any time.