Excellent drive. See reviews at STH, Tom's, Anandtech.
I own 2. Also have 1TB Adata SX8200 Pro (old/good version) and 1TB WD SN750.
P31: 4K Rand Read: T1 70 MB/s ; T64 430K IOPS
SX8200: 4K Rand Read: T1 54 MB/s ; T64 182K IOPS
SN750: 4K Rand Read: T1 41 MB/s ; T64 203K IOPS