I took both classes, but I really didn't care for Reactive as much. The first Coursera class really turned me on to the elegance of functional programming with Scala's unique type system, but much of that elegance is really lost dealing with some of the structures introduced in the second class, in my opinion.
Reactive is split into three "subclasses". The beginning part, taught again by Odersky, was a pretty useful extension of what was taught in the first class. As with the first class, the lectures were very well thought out. Although, some of the examples abandon the beauty of side-effect free programming, which was a letdown after really being turned on to that style in the first course.
The middle section on Futures and ScalaRx was pretty rough. Those lectures, done by Erik Meijer (I believe), were less clear and less well planned. I don't know if there's an impedance mismatch between Scala and the reactive style or if ScalaRx is just the wrong abstraction, but the joy of Scala was completely lost for me in these two lectures. I'm used to Javascript's Promises/Deferreds, which are essentially the same thing as Scala's Futures/Promises, but the former are far more intuitive syntactically.
I did, however, find the final three lectures on Akka to be very well taught. I had no experience on actor model programming, but I came away very intrigued by the possibilities.
A complaint that spans all three sections was that the assignments could be better focused on the the concepts at hand. Each can require a fair bit of constructing your own test and debugging frameworks to figure out how to pass the rather opaque and unhelpful automatic grading system. I eventually lost patience and quit doing the assignments after floundering with the tools.