What he said. They are EXACT replicas of the original; to include wire and stripe colors and connectors. That makes it easy to trace problems with a factory wiring diagram.
Having built 2 aftermarket systems in cars I would have to be doing a major transformation on a vehicle to justify not going with a OEM system. I do enough electrical at work to get my "fix" so it would be a Plug and play.
If you are adding some non factory items do what the Manufacturers do now. Add a smaller fuse panel somewhere else. It's not complicated at all....
