hooberus I suspect that the most truth lies somewhere in between. A parallel does not necessarily have to equal the other item but just bear a number of similar qualities.
A parallel doesn't have to be exact to be a parallel- however, it should be parallel enough to substantiate the claims made regarding it. The "Christ mythers" not only claim parallels but actual borrowing. The so-called "parallels" offered by them are either usually are not very parallel all (relying on equivocation in terminology), come from post-christian sources, lack primary source documentation, etc.
There is a formula that is invoked in many, many mythologies involving birth, death and rebirth. The cycle in the Horus mythology parallels that of the Jesus mythology.
Response to the alleged parallels between Horus and Jesus. http://www.tektonics.org/copycat/osy.html