Each component of the ignition system must perform for proper ignition to occur in the combustion chamber.
The coil packs supply the energy and the spark plug wires transfer the energy to the spark plugs.
There are multitudes of debates over coils, plugs and wires. The fact of the matter is most stock or moderately modded engines will not see an increase in power from any said coils, plugs and wires but they MAY very well pick up some HP that was lost over the years due to weak components.
IMHO, QC of the aftermarket ignition parts are paramount to satisfactory performance. In view of that, higher quality does imply the ignition works easier and will last longer. Virtually any aftermarket coil will deliver enough power comparable to stock. Quality spark plug wires will deliver the power to the spark plugs. The problem is with age and degradation of the components operating under extreme conditions. Coils begin to break down and power output suffers or misses occur. Wires begin to breakdown and leak energy robbing the power from the spark plugs causing intermittent issues or high rpm misses. Spark plug gaps erode over time and demand more spark energy to 'jump the gap' which taxes the wires and coils even more.
You can buy what ignition parts you want. If it works, it works. It's that simple. MSD, Motorcraft, Ford Racing, Performance Distributors and even the infamous Nology - they all have their following.
I simply buy what I consider to be high quality ignition parts that look good. Coils? I figured the time had come to retire the old stock ones, so I bought the ones that went with the new wires I had. Plug wires? I just got tired of the red ones and bought blue ones.