AC plug benefit?

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.

Good point, Hdm. I agree.

I purchased 2 off Albert, great guy BTW and a pleasure to talk with, they improove things but dont expect miracles as what is huge change to one persons system can be subtle but better in another, all the same things will no doubt be better but its a question of how much.

Chadnliz is right, these kind of "tweaks" could give some improvements, but they are never "day and night" differences. That is one of the rules of high-end audio.

Chris