Very underated, very unknown but highly customizable, full of unique features, great stock plugins, best CPU optimization in a DAW, themable and cheap too. What would you want more!?!
It's seems like a great DAW that packs a punch, but I have not spent enough time on it to be able to give a true, thorough review. But for only $60, there is no going wrong with Reaper.
While on its own, REAPER is good for recording, adding plug-ins makes it good for in-program production. Nice, clean design and little in the way of issues. Would certainly recommend.