Sorry, but I have to disagree, as years of experience in experimenting with these things has shown me differently. Don't get me wrong, the improvement with star-earthing isn't huge, but it's significant enough to be heard, as indeed is any time lowering mains impedance (via any means) has been achieved.
Experience has shown me that the ideal mains distribution block (should one be needed) is:
a) Non-filtered, with no neon lights.
b) Uses high-quality single un-switched sockets and a non-ferrous casing.
c) Star-earthed, using a good quality wiring loom.
d) Uses a hard-wired, high-quality mains flex and plug.
Anyone who can't hear the difference between one of the above and your average mass-produced shite, from B&Q, is deaf!
Marco.