[Vildecor]

As far as realism goes, I think how D&A works is decently close. Gaining one tech level above where you already were in a certain area isn't a far stretch when analyzing alien ships. ("Hey, these alien Quantum Engine IIIs look remarkably similar to our Quantum Engine IIs!")

The only thing that isn't very realistic, in my opinion, is being able to get the colonization techs from D&A (if you haven't gotten them already by then).