I'd agree that comparing the new style parts to the older parts, given both sets are new, there is little difference, but the newer style parts will hold the tune longer and the larger plug gaps possible with the new TFI (Or HEI) coil will fire leaner, less ideal mixtures. I like the way that the newer wire style seals against moisture and the silicone jackets are less prone to breakdown from heat. I found that swapping to the new style wires, cap, cap adapter and rotor on 5.9l (360) Grand Wagoneers made a big difference in how long the parts lasted in the underhood heat. The old wires would usually be shot in 30k miles, the new sets would last twice that, if not more.

On my '68 AMX, (401) I'm running a stock Grand Wagoneer Motorcraft distributor, a MSD 6 ignition box, and the TFI style wires, cap, and rotor. It made a great improvement over the stock Delco points distributor.

As a side note, the V8 cap, cap adapter and rotor will fit many of the old Ford points distributors, too. Pertronics makes a neat electronic ignition module that fits inside the stock distributor in place of the points and connects with two wires to the coil for a neat and simple installation. A friend recently put a set on a '56 Ford 312 Y block.