I guess it depends on your needs. For strictly photographic needs I find PS Elements meets my needs and have not considered moving to it's "big sibling".
I have heard if you have more graphics need PSE will fall short, but for strictly photographic editing and adding effects, for me, PSE is plenty.
I don't do a ton of advanced editing (so you know where my opinion comes from). When I do, as I have said, I find PSE and filters and add-inds meet my needs.