Is PS really that much more powerful than Pixelmator? Is it worth installing? Which do you prefer to work in?
Yes - I want to like Pixelmator (and dump Adobe), and it is excellent value (I bought it when it was on offer) but even the cut-down PS Elements* is more powerful than Pixelmator in some ways.
For example - I often find myself wanting to take a PDF file, render it as a bitmap then reduce it save it out as a PNG thumbnail for the web.
Yes, Pixelmator will open a PDF, render the first page to a bitmap, allow me to resize it then export it as a PNG.
However, if I do it in PS - first, I get to choose which page of a multi-page PDF to render, and I can choose the colour format, height width and PPI of the render. Then, there's a really nifty 'save to web' tool that lets me choose the bit depth, transparency options, palette options and the target size, gives a preview of the result and the file size of the result - all without changing the original, so I can easily output several sizes of bitmap if I want. Pixelmator just doesn't offer this control (or if it does, I haven't discovered it).
(*I have PS Elements 11 - I haven't tried the newer versions, hopefully they haven't suffered too much from the dumbing down trend)