To be honest, it was about a year between taking the pipes off and putting them back on. I knew of the copper gaskets prior to removal, so I'd like to think I would have taken the old out, but can't be for certain.
The copper gaskets are a few bucks cheaper. I guess I'll go with them unless anyone has any objections. I'll be sure to make sure I clean up the heads before the new gaskets get put on. Thanks for the advice, Ken.