JIA, there are entire books, or at the very least chapters in books, devoted to this.
If you're actually interested in learning the answers to these from geneticists, find the materials on your own. They are not hard to track down. A google, amazon, or other search will readily produce them. Read, learn, grow. It's fun.
If, however, you want incomplete sound bite answers from evolutionarily literate though hardly expert KMC members, that you can then throw into question in your own mind because they don't answer all your questions and concerns (and never could), then by all means keep posting. Clearly one is less futile.
Because frankly, given your history, this seems less like a legitimate scientific inquiry, and more a veiled attempt to make it seem like we can't really prove evolution. I may be wrong. But we've all read the boy who cried wolf...you might actually see a wolf this time, but nobody's listening. Thus, comments like this:
Originally posted by inimalist
but ya, its a JIA thread...
...in any case, your original question is flawed because it presupposes a "better" form of reproduction, and also presumes that if one indeed were demonstrably better that all organisms would adhere to the superior design. Random mutations over time accounts for a lot in evolution, so the fact that one is predominant may have nothing to do with it being better, and simply more to do with it having happened at an opportune time in evolutionary history. We are usually not optimally designed.
That said, sexual reproduction has lots of advantages, as extrapolated upon by many in this thread.