WD10EADS - very large current pending sector issue

I bought a WD10EADS about 3 months ago.

The SMART health check reveals a Power On Time of 308 hours, Current Pending Sector count of 497 and Offline Uncorrectable count of 496.  Reallocated sector count is 0.

I have been noticing some stuttering when reading from the drive.  I just dumped 700 gig on this drive yesterday from 2 500gig seagate drives (which have been rock solid for about 3 years).  Before I did that, the current pending sector count was 6 and the uncorrectable was 0.

Is this drive ruined?

I’m now getting loads of CRC errors.  Sounds like this drive is ******.