In the recent Computer Music issue, Reaper 4 was given a 4.5/5 star review. The final summary is below. Read the whole review at Music Radar
Pitch envelopes. Surround sound support. Improved skinnable interface. Small hard drive footprint. Developer is attentive to users’ needs. Good value.
Audio editing could be deeper. Some drab-looking effects.
Reaper is a genuine alternative to more blinged-out DAWs, and it continues to improve at a scarily rapid pace.