Comparison with codec2 & other very narrow encoders?

It is helpful at a higher level. If you're trying to design a system, is it worth pushing the bit rate as low as possible? Seeing the qualities achieved for typical signals can help people decide which trade-offs to tackle. Should you shoot for jamming enough into single network packets with moderate lag and a simple overlapping scheme for handling drops or go ahead and expect many packets with a different error handling mechanism, etc.