We have a question that is almost the same as this one...but the question and answer both pertain to an earlier version (< .23), and note that the specific answer was to change with the newer version.
I know that if I do an experiment and recover the data by bringing the ship back to Kerbin and recover the ship, I get 100% of the experiment value. I also know that if I transmit the data back, I get a smaller percentage (which can vary, depending on various things).
Also, experiments can be repeated, but their value decreases with repeated runs.
So the question is: is it fine to transmit science experiment results back, and not have to worry too much about losing potential science gain in the long run?
(The answer to the earlier question was that it was fine; regardless of how you did it, you ended up with the same amount of science in the long run, for the most part, if you ran all experiments until they returned nothing. But, again, the answer also mentions that this was to change in some way with .23+, but it didn't say in what way.)