I re-ran the splice ns->host test using splice, and it works flawlessly.
It seems like Stefano's fix solved the problem.

/jon


[  5]  90.00-91.00  sec  4.06 GBytes  34.9 Gbits/sec
[  5]  91.00-92.00  sec  4.05 GBytes  34.8 Gbits/sec
[  5]  92.00-93.00  sec  4.04 GBytes  34.7 Gbits/sec
[  5]  93.00-94.00  sec  3.93 GBytes  33.8 Gbits/sec
[  5]  94.00-95.00  sec  3.92 GBytes  33.6 Gbits/sec
[  5]  95.00-96.00  sec  3.95 GBytes  33.9 Gbits/sec
[  5]  96.00-97.00  sec  3.91 GBytes  33.6 Gbits/sec
[  5]  97.00-98.00  sec  3.92 GBytes  33.7 Gbits/sec
[  5]  98.00-99.00  sec  3.67 GBytes  31.5 Gbits/sec
[  5]  99.00-100.00 sec  3.64 GBytes  31.3 Gbits/sec
[  5] 100.00-100.00 sec  1.88 MBytes  35.0 Gbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-100.00 sec   389 GBytes  33.4 Gbits/sec                  
receiver
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Server listening on 5201 (test #2)
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