Quote - > Quote - is that once you've erased pixel information, you can't get it back.

 

that's what the history/step back feature is for....?

Yes, but very rarely can the history go back that far -- I set mine low for a speedier workflow, and I usually do a whole lot more to a file than just a simple fade. Plus, after you save a file and get out of it, the history's no longer there anyway. I deal with finicky clients who ask for impossible changes, so whenever I can achieve an affect without losing out on original information, I do it ... because it would be just my luck that they ask for a change that requires me to, say, make the fade more/less gradual; so if I erase information in the first place, I'd end up having to do the entire file all over again, whereas if I use a layer mask at the start, all I have to do is tweak that mask, and I'm good to go on the second draft.

So ... I use a layer mask rather than erase. There's always a VERY good reason for the way I do things, and that reason is I'm lazy and don't want to do extra work later. ;)