There appear to be significant differences between Radio Silence and Little Snitch. With Radio Silence you choose the apps you don't want to phone home. This is fine if you are concerned about specific applications. Little Snitch, on the other hand, is far more granular, filtering all outbound traffic and asking you to set up a rule for each distinct instance. This can, indeed, be annoying. But it's far more thorough and, ultimately, provides a much higher level of monitoring and security. Which app is best for you depends, basically, on your level of paranoia. I've been using Little Snitch for years. While it can be annoying, it's important to realize that it's not Little Snitch that's causing the problem - its all the various apps and system functions that want or require internet access. The problem is inherent to the system. But if this is too much of a good thing for you, Radio Silence now offers an alternative, though it is less comprehensive. How effective either app is will depend on how you use it.

I wonder how Radio Silence compares to Little Snitch, which is over three times more expensive. Going by the looks of the above image alone, I suspect that Radio Silence may be considerably more simplistic/bare bones compared to Little Snitch. Of course, at this point, Little Snitch is a mature product, while Radio Silence isn't.