Original and Retest: ASUS RT-AC68U
For easier comparison, here are original and retest plots for each product, band and link direction. First the ASUS 2.4 GHz band. This comparison more clearly shows improvement for both 2.4 GHz up and downlink.
ASUS RT-AC68U original and retest comparison - 2.4 GHz
The most notable thing in the 5 GHz comparison is the improvement in the 0 dB uplink measurement. This helped the ASUS' ranking, since this test is used for maximum throughput ranking.
ASUS RT-AC68U original and retest comparison - 5 GHz
Original and Retest: NETGEAR R7000
The 2.4 GHz NETGEAR plots show essentially unchanged results, with a tad more change in downlink than uplink.
NETGEAR R7000 original and retest comparison - 2.4 GHz
The 5 GHz comparison again shows uplink improvement for the 0 dB test, which definitely helps the R7000 to not lose too much ground against the RT-AC68U in the reranking for this benchmark. Otherwise, performance is unchanged.