I ordered the Screamin' Demon coil pack from them last summer. Their customer service was great and I received the package within like 3-4 days. My engine was running horribly from a cracked PCV vacuum hose, which I replaced when I did the coil, along with new plugs, wires, and O2 sensors. Since all of this was done at the same time, and my truck was stalling and idleing funny, I obviously didn't notice any difference other than the fact my truck ran normal again.
I haven't had any problems with it though. I gapped my plugs to .065" IIRC?
2002 Ranger XLT 4.0 4x4 & 285/75/16's
Did the "roll truck onto it's side" Mod