I would love to be able to use GNURadio for something, I've just never found flow diagrams to be more expressive than writing procedural instructions over whatever SDR API. GNURadio's flow diagrams introduce a lot of hidden complexity that is difficult to observe and understand. For example, every arrow you draw represents a buffer and so for all but the simplest graphs this will quickly lead to difficult-to-interrogate sample over/underruns. There are workarounds for fine grained control over these buffers but they cannot be called simple (like message passing via tagged samples and flow control blocks).