AC plug benefit?

Porter ports are a terrific investment. I have several.

No beter bargain out there than the Porter Ports.

For a very neutral, dynamic outlet, the Porter Ports are highly recommended. They are also priced reasonably compared to the newer, fancier ones from Oyaide, etc. Remember that outlets require some break-in time just like your power cords. I have found that outlets with nickel in them don't sound very musical in my system. My ears also scream for mercy with anything that's rhodium plated. YMMV.

I Agree with the above comments.
Read:
http://forum.audiogon.com/cgi-bin/fr.pl?raccs&1065488253&openfrom&1&4#1

While the Porter Ports are very good (I use a DIY variation of them) bear in mind that the real answer to your question is that, yes, there will probably be some improvement, but that improvement would be significantly magnified if the receptacles in the surge protector were also replaced with Porter Ports (or an equivalent).

You are diminishing the positive effects of the Porter Port by putting inferior receptacles ahead of it in your system.