As many of you doubtless know by now, Google's first Android 5.0 devices ship with full-disk encryption enabled out of the box - encryption that can't be disabled without flashing a new ROM to the device. We've heard from at least one source that this encryption shouldn't really affect on-device performance noticeably, but new benchmarks from Anandtech seem to suggest otherwise.
The heavily tech-focused review and news site didn't publish storage benchmarks for the Nexus 6 in their review, because the app used - Androbench - was deemed to be producing inaccurate results on Lollipop devices (and it definitely is).
AnandTech Posts Side-By-Side NAND Performance For Nexus 6 Encrypted Vs. Unencrypted - It's Not Pretty was written by the awesome team at Android Police.