I have huge problems with the NASA manned program from Apollo on, but their science probes have returned a bounty of information about our sister planets, and other objects in the solar system including our own earth. Just looking at Mars, you do realize in only a couple of decades we've mapped the entire planet (the land area pretty much the same as earth's land mass).

LRO has a number of instruments which see in other radiation bands than what our eyes normally see. A lot of the scientific work is about prospecting (of what is it made), and having a slightly sharper image won't be as good as knowing how many neutrons are coming from it. The design is a synergy of instruments to try to answer specific questions.

One of the big outstanding questions resolves around characterizing Lunar crater water (or lack there of). I'll be curious on how well this instrument refines the question of the "Lunar polar water." In any event, I think by and large we've gotten good cost benefit return for NASA science probes. The manned program is another story probably wasting 2 times what the unmanned program has cost.