Hello Iain. I’ll jump in here and give my 2c worth.
Personally, I don’t even bother with DPP. Just download Adobe Camera Raw for Elements, and do all your WB and exposure settings with it. Then open the file in PSE, and tweak your levels, highlights/shadows, saturation etc and finally sharpen. I have pretty much always used this routine, worked fine for most shots.
I have recently purchased DXO Optics 5, and though I am still getting the hang of it, I like it. Still follow pretty much the same routine as above though.
PS – I use Canon’s Zoombrowser to manage my libraries, haven’t yet developed the need for more sophisticated DAM software. I’m not a pro, just a keen hobbyist, and losing my data is not that much of a calamity that it would justify the expense.