What I would have liked to have seen is the lowest end antenna have a limited range, and better antennas have better range with lower energy cost. It would have also been nice if you could bounce signals off other vessels, giving a reason to send probes into orbits around other planets with better antennas. To me, this makes more sense of what the antennas would be used for, rather than just a % science gain. I agree that it would make more sense to cap the science that could be gained by transmit, and require an actual recover to get the full credit. It would also make sense for the deployable labs, which would then give you 100% of the earnable science, making it so the science could be accumulated, but it wouldn't "count" towards your science earned until you had a pathway to transmit the signal all the way back to Kerbin. Wheffle is right about the actual operation of the antennas, though. The "better" antennas transmit more data per packet at higher packet energy cost and higher total energy cost, but the total data sent back is the same for any given antenna, and spamming radio returns will eventually cause as much science gain as recovering samples. Ultimately, once solar panels are equipped, it doesn't make any sense to recover samples, because you can just spam radio returns until all the science for a particular area is gathered.