We're working on running some more thorough YCSB benchmarks, but here are some of the percentiles on the uniform "workload A" running on a 9 node cluster for 1 hour:

Throughput: 28280 ops/sec Read: 2821us avg, 467us min, 3519us 95p, 6843 99p Update: 1688us avg, 714us min, 1983us 95p, 8855us 99p

Workload D, which has some inserts (and reads recently written data):

Throughput: 36286 ops/sec Read: 1765us avg, 491us min, 2537us 95p, 4259us 99p Insert: 1614us avg, 838us min, 1595us 95p, 11575us 99p

Hope that helps. I'll try to push our latest YCSB bindings to github later this afternoon/evening if you'd like to reproduce on your own.