Leighsww, i read through that post and I have to admit I didn't exactly see a clear answer. The upshot, though, seemed to be that it (in general) didn't harm anything and it did seem to be a good idea. Is that right?
Yes, pretty much.
After my testing/using it, I realized that the spoofed emails won't actually be blocked automatically (as I had hoped it would) and would require the user to check the SPF headers to see if it is forged (at least that was my findings).
However, some service providers make it easier to do that and won't require the user to have to know this info to benefit by it. Here's a link regarding AOL:
http://www.openspf.org/howworks.htmlAll-in-all, since it doesn't have any downsides that I could determine, I found it better to implement it than to not, since I had a lot of spoofing happening to my domain name in the past.
Hopefully, more will be done with SPF in the future, so that it will actually/automatically block spoofed email from ever reaching the recipient's inbox. This would then be perfect, in my opinion.