A few years ago I installed Davis Unified Ignition Screamin' Demon coil packs onto my 1999 Ram 2500. I have now had them installed for 25,000 miles and wanted to share my experience with them. At first I installed them as per instructions along with a new set of NGK V-Power plugs and a fresh set of standard plug wires. I also increased the plug gap to .065 as recommended in the instructions. Truck started quicker and seemed to idle smoother. I did not notice any seat of the pants improvement but I did not expect to. After a few months, I started to experience an intermittent miss and a CEL for the coil packs. Upon pulling the new plugs, I found that they had worn very quickly. I replaced the old plugs for a new set of NGK plugs and retained the stock .045 gap. I noticed no difference in idle quality and the problem went away and has yet to return.
After my experience with these packs, I would recommend staying with the stock plug gap if you run a standard style plug. You may be able to run the larger gap with a iridium or platinum plug as they are designed to not wear as quickly.