27% regression in 80th percentile query latency with 1 bucket, 20M docs and stale=false parameter

Test description:
80th percentile query latency (ms), 1 bucket x 20M x 2KB, non-DGM, 4 x 1 views, 500 mutations/sec/node, 400 queries/sec, stale=false

Observation:
80th percentile latency increase from 5457 ms to 6954 ms

links:
http://cbmonitor.sc.couchbase.com/reports/html/?snapshot=zeus_301-1330_686_access
http://cbmonitor.sc.couchbase.com/reports/html/?snapshot=zeus_251-1083_6c5_access

logs:
http://ci.sc.couchbase.com/job/zeus-64/1222/artifact/172.23.96.25.zip
http://ci.sc.couchbase.com/job/zeus-64/1222/artifact/172.23.96.26.zip
http://ci.sc.couchbase.com/job/zeus-64/1222/artifact/172.23.96.27.zip
http://ci.sc.couchbase.com/job/zeus-64/1222/artifact/172.23.96.28.zip
http://ci.sc.couchbase.com/job/zeus-64/1222/artifact/web_log_172.23.96.25.json