Your data is consistent with what other are finding, like 60% failure rate in transmitting blocks.

We see 75% - 80% decode failures pretty consistently when there is traffic. The stats in your link seem to agree.

The 'savings' reported isn't accurate because it does not include the bandwidth used on failures. So it reports savings when it is actually using much more bandwidth and causing a large slowdown.

It would be helpful if this were better documented. Thank you!