I have had PSE 7 on my computer for a while, found it a bit difficult to find my way around. Recently I've started shooting photos in RAW, and then I found it even more problematic. Seems to be some difficulty with the Camera Raw plug-in. Following helpful comments from PeterD and a friend at home, I have taken a 30 day trial on Lightroom, and so far I'm finding this much better, particluarly as it handles RAW images and jpeg images in the same way and has the same editing functions available for both types of image.
I have about 12 days before I have to decide whether to purchase. I would welcome comments from other users on the ralative merits of thes two pieces of software.