I've used Elements 4 for a couple of years, enhanced with some third-party plug-ins - things like curves, software for lens distortion, sharpening, noise reduction - things that Adobe doesn't bother to include in any meaningful way with Elements. Still, Elements 4 had its good points. I up-graded to Elements 6 because it's supposed to support 16-bit editing. It doesn't. On top of that, it's far, far slower than 4. It claims that you need 256 MB, minimum, to run it, 512 MB recommended. Well, I've got 512 (no great shakes these days, I'll admit) and that ain't anywhere near enough. As soon as I tried to use the plug-in that would let me correct lens distortion, I got an "out of memory" error and everything ground to a halt. Funny - works just fine with 4.
Basically, if you've got an earlier version of Elements, stick with it. That's certainly my plan. If you're looking to up-grade, well, give some thought to the Gimp. It's free, after all, and does pretty much everything Big Photoshop does. At least if you decide you don't like it, you haven't lost anything.